iTiMT5r^' 



i 



LIBRARY OF CONGRESS. 



:ix%^ 

INITED STATES OF AMERICA. 



IRREGULARITIES 



OF 



THE TEETH 



TALBOT 



IRREGULARITIES OF THE TEETH 



AND 



THEIR TREATMENT. 



EUGENE S. TALBOT, M.D., D.D.S., 

M 

Phofessoe of Dental Surgery in the Woman's Medical College ; Lecturer on Dental 
Pathology and Surgery in Eush Medical College, Chicago. 



SECOND EDITION. UEVISED AND ENLARGED. 







Dr^ 



WITH 

TWO HUNDKED AND THIRTY-FOUE ILLUSTEATIONS. 

1G9 OF WHICH AKE ORIGINAL. 




PHILADELPHIA : 

P. BLAKISTON, SON & CO., 

1012 WALNUT STREET. 
1890. 



"*.. 

>^^^ 



■^i^^ 



Entered according to Act of Congress in the year 1890, by 

EUGENE S. TALBOT, 

In the Office of the Librarian of Congress, at Washington, D. C. 



TO THE 
MEMORY OF MY BROTHER, 

THE LATE DR. CHARLES F. TALBOT, 

THIS VOI.UME 
IS AFFECTIONATEIyY DEDICATED. 



PREFACE. 



In the preparation of the second edition of his work the 
author has aimed to add such matter as may make it more 
complete without altering the general plan. Some of the chap- 
ters contained in this edition appeared in the Dental Cosmos of 
1888-89. A historical sketch of theories has been prepared 
which it is hoped will interest the student, inasmuch as it gives 
him a fair knowledge of the rise and progress of theories 
regarding the causes of irregularities, from which it will be seen 
that many theories supposed by the majority of practitioners to 
be of comparatively recent date are among the first advanced. 

The author has taken particular pains to make the treatment 
of etiology complete, and the distinctions of the causes of irregu- 
larities clear. This subject having been treated hitherto only in 
a general way, the author hopes that others will be encouraged 
in further researches in this interesting field, where there is ample 
opportunity for labor and observation. In the classification of 
irregularities the aim is to give the student a standard of com- 
parison w^hich, when fully understood, will aid him in placing 
the irregularity under consideration in its proper class, every 
typical form being illustrated. 

In the correction of irregularities no fixed rules can be laid 
down for treatment as in surgery, because the resistance offered 
by each case is a force known only approximately beforehand. 



8 PREFACE. 

Only the general law can be laid down for correction, this law 
being subject to modification by experiment. For this reason 
the author has described the mechanical laws, illustrated their 
application in the simplest manner possible, and has given 
practical cases where they have been found efficient. He be- 
lieves this method to be the best to impress the principal features 
of the operative treatment of irregularities upon the mind of the 
student. The author has omitted many appliances in use, not 
because he believes them less efficient than some of those given, 
but because, in his opinion, they add nothing to the illustration 
of the principle. 

The author desires to acknowledge his indebtedness to Dr. E. 
Mergler Schell for assistance ; to Dr. Marie White for the com- 
pilation of the historical sketch ; to Dr. H. J. McKellops for 
the use of his valuable library ; and also to the S. S. White 
Dental Manufacturing Company for the use of many wood-cuts. 

Eugene S. Talbot. 

125 State St., Chicago, April, 1890, 



CONTENTS 



PAGE 

INTRODUCTION 13 



PAET I.-ETIOLOGY. 

CHAPTER I. 

HISTORICAI. SKETCH OF THEORIES REGARDING THE ETIOI.OGY OF 

IRREGUIyARlTlES OF THE MAXIIvI,^ AND TEETH. 

SUPERNUMEEAEY TeETH : 17 

Thumb-Sucking and Similar Causes 18 

Retention of Temporary Teeth 20 

Growth of Maxilla 21 

Sleeping with the Mouth Open 21 

Premature Extraction of Temporary Teeth 22 

Attributed to Civilization 24 

Development of the Sphenoid Bone 24 

Constitutional Causes 25 

Want of Proportion between Jaws and Teeth 28 

CHAPTER II. 

THE AI,VE0I.AR PROCESS. 

The Inferior Alveolar Process , 32 

Hypertrophy of the Alveolar Process 39 

CHAPTER III. 

CONSTITUTIONAI, CAUSES. 

A. Anomalies of Jaws in Healthy Individuals Transmitted from 

Generation to Generation , 42 

I. Arrest of Development of the Maxillary Bones due to 

Race Crossing, Climate and Soil 42 

11, Arrest of Development and Excessive Growth of the 

Maxillary Bones 50 

III. Development of the Inferior Maxilla by Exercise .... 54 

IV. Asymmetry of the Lateral Halves of the Maxillary Bones 56 
V. Asymmetry of the Maxillary Bones 61 

VI. Asymmetry in the Rami 63 

VII. Asymmetry in the Body and Improper Occlusion 64 

VIII. Imperfect Occlusion .• • - ^^ 

IX. Protrusion of the Inferior Maxilla 68 

9 



10 CONTEXTS. 

CHAPTER IV. 

COXSTITUTIOXAL CAUSES (cOXTIXUED). 

PAGE 

B. A^'OMALIES OF Jaws that aee the Eesult of Fu^"•CTIO^-AL De- 

EAXGEilEXT 73 

1. Ieeegulaeities EE5ULTi2fG feom: Mal^tuteitio^- 73 

2. Ieeegulaeities Eesultistg feom Ovee-stimulatiox .... 73 
Ieeegulaeities Resulting feom Malxuteitio^ 74 

I. PEEVALE:5fCE OF Maxillaey Defoemities IX Idiots 74 

II. Peevale^'ce of Maxillaet Defoemities amoxg the Deaf axd 

Dumb 78 

III. Maxillaet Defoemities amokg the Blixd 80 

Maxillaet Defoemities amoxg the Ixsaxe 80 

Defoemities of the Maxillx amoxg Childeex APPAEE^•TLT 

IS'ox-Defective 81 

Co^fSAXGUixiTT m its EELATio:5r TO Defoemities ix Gexeeal . 84 

SCEOFULA AS A CaUSE 85 

Deuxkexxess IX Paeexts 86 

Pee-Nata-l Ixfluexces axd Ixtea-Uteeixe Educatiox ... 87 
Abxoemally-shaped Heads 91 

CHAPTEE V. 
coxstitutioxai, causes (coxtixued). 
Neueotic Texdencies as a Cause of Aeeest axd Excessive 
Developmext of Maxilla 95 

CHAPTEE VI. 
forms oe irregularities resultixg from coxstitutioxae causes. 

I. The V-Shaped Aech 102 

Oeigix axd Developmext of the V-Shaped Arch axd its 

MODIFICATIOXS 103 

The Xoemal Aech 104 

FoEMATiox of the V-Shaped Aech 105 

Desceiptiox of the V-Shaped Aech axd its Modificatioxs 108 
Ieeegulaeities of the Lottee Jaw 114 

CHAPTEE Vll. 

EORMS OF irregularities RESULTIXG FROM COXSTITUTIOXAL CAUSES 

(coxtix-ued). 

II. The Saddle-Shaped Aech 118 

Desceiptiox of the Saddle-Shaped Aech axd its Modifica- 

tioxs 122 

CoMBiXATiox OF V AXD Saddle-Shaped Aeches . ... 124 
The Saddle-Shaped Aech of the Lowee Teeth 126 

CHAPTEE VIII. 

local CAUSES. 

What Coxstitutes a Local Cause 128 

Relative Importaxce of Ixdividual Teeth ix Effectixg Ieeegulae- 
ities 128 



CONTENTS. 11 

PAGE 

Irregulaeities Produced by the Malposition of the Ceittral Incisors 
Eesulting from Flexion of the Alveolar Process 129 

Irregularities Produced by the Malposition of Central Incisors 

DUE TO Vicious Eruption 132 

Irregularities Produced by the Malposition of Laterals .... 134 

CHAPTER IX. 

I^OCAI, CAUSES (continued). 

Irregularities Produced by the Malposition of the Cuspids ... 13 

Irregularities Produced by the Malposition of Bicuspids .... 141 
Irregularities Produced by the Extraction of the First Perma:nent 

Molar 143 

Local Irregularities of the Lower Jaw 148 

The Inferior Cuspid 153 

Lower Bicuspids 154 

CHAPTER X. 

anterior protrusion. 

Migration of Teeth 155 

Conditions Necessary to the Normal Relation of Teeth .... 156 
Results of Want of Occlusion and Violation of the Laws of Waste 

AND Repair 156 

The Movement of Individual Teeth on Straight Lines 157 

Rotation of Individual Teeth upon their Axes 158 

The Forward Movement of Groups of Teeth and the Alveolar 

Process Supporting Them 159 

Anterior Protrusions from Constitutional and Local Causes . . . 159 

CHAPTER XI. 
Supernumerary Teeth 162 

CHAPTER XII. 
Thumb and Finger-Suckino as a Cause of Irregularity .... 166 



PAET II.-TEEATME]N"T. 

CHAPTER I. 

PREWMINARY CONSIDERATIONS. 

Diagnosis 170 

Age , 171 

State of Health 173 

Desire for Correction 175 

Impressions of the Mouth and Models 176 

The Study of Models 181 

Fees 186 

CHAPTER II. 

Physiological and Pathological Changes 1S9 



12 CONTEXTS. 

CHAPTER III. 

m:e;chanicai, forces. page 

Application of Foece 192 

The Lever 195 

The Pullet, Wheel and Axle 197 

The Inclined Plane ... 198 

The Wedge 199 

The Screw 200 

Elastic Force 202 

Ligatures 205 

The Elasticity of Metals 206 

CHAPTER IV. 
consideration of different methods. 

The Patrick INIethod 207 

The Farbae Method 208 

The Byrnes Method 210 

The Headridge-Coffin's Method 215 

Pl^no Wire 218 

The Author's Method— The Coil Spring 218 

Spreading the Dental Arch 220 

Regulating Individual Teeth 223 

CHAPTER V. 
treatment of speciai, forms of irregui^arities. 

Rotating Teeth in their Sockets 227 

The Farrar Method 227 

The Guilford Method 230 

The Author's Methods 231 

Moving Crowns and Roots 232 

Compulsory Eruption of Teeth 235 

The ]\Iatteson j\Iethod 235 

The Author's Method 236 

CHAPTER VI. 
protruding teeth. 

Kingley's Case 241 

Farear's Cases 243 

Treatment of Anterior Protrusions of the Superior Dental Aech . 248 

The Author's Method 248 

Protrusion of the Inferior Maxilla 250 

Allan's Case . 250 

Methods of Retention of the Teeth after Regulating 250 

Kinglet's Retainer 252 

Richardson's Retainer 252 

Rubber Plates with Gold Bands and Bars 253 

Farrae's Retainers 254 

Dr. Guilford's Retainer 255 

The Author's Retainer ' 256 

Length of Time Required to Retain the Teeth in their Place . . 256 



INTRODUCTION. 



In presenting his views regarding the etiology of irregularities 
of the teeth and their correction, the author lays particular stress 
on underlying principles. It is believed that a full comprehension 
of these is necessary to success. A study of isolated cases is valu- 
able for the training of the observation, and for deciding what 
appliances shall be used, but it is impossible to get at the relations 
of cause and effect, and make a correct diagnosis without a knowl- 
edge of principles. The operator, without this knowdedge, must be 
more or less empirical in his treatment. The laws that govern 
the body as a whole must be understood, for each organ is governed 
by them more or less. Suffering of one part implies suffering of 
the w^hole. In order to make clear these principles, a large number 
of cases are cited. These are not hypothetical cases, but are such 
as have occurred, from time to time, in the author's practice. 

Health of the body, like that of the mind, depends largely on 
the proper performance of the various bodily functions. The kind 
and degree of functional activity must be suited to the individual. 
When this accord exists we have happiness of mind and health 
of body. In a recent article in a medical journal, the baleful influ- 
ence of idleness in prison life is discussed. It is stated that the 
consequences of the labor law of 1888 were the increase of insanity, 
a higher death rate, a shattered morale and an unprecedented deficit 
in the sum total of earnings as compared with expenditures. This 
illustrates a far-reaching principle. Not only is activity necessary 
to the well-being of the individual as a whole, but to every organ. 



14 INTRODUCTION. 

Excessive action or impaired function imply disease. The stomach, 
if overloaded or required to digest unsuitable food, becomes enfeebled. 
Every organ depends for its integrity immediately on the nervous 
system. AVben nervous activity is impaired, or lacks balance, the 
general balance of fimction is disturbed. Nowhere are results of 
this lack of equilibrium more visible than in the teeth. 

Malnutrition resulting from disease, from insufficient or unsuitable 
food and unhealthy environment, is the cause of idiocy, insanity, 
blindness and other defects. Derangement of the nervous system 
usually underlies these conditions as found among the poor. But 
there is another class of individuals who suffer from neurotic condi- 
tions. They are those who are well fed and housed, but have over- 
taxed their nervous systems by improper modes of life and various 
forms of excitement. The two classes have this in common, that 
the functions of the nervous system are impaired, and they show 
similar results of defective nutrition. This want of balance pro- 
duces an osseous system that shows excessive development in some 
of its parts, and arrested development in others. Nowhere is this 
more manifest than in the maxillae. Thus we have the causes of 
constitutional irregularities established. We see the disturbances of 
the ftmctions of the organs of the body as a whole result in con- 
stitutional irregularities. The impairment of the function of the 
teeth themselves gives rise to local irregularities. The importance of 
the correct performance of the function of these organs will be seen 
from a brief consideration of the results of impaired activity. 

1. Teeth to be clean must be used. When one half of the arch 
alone is in use, the other half shows an unusual deposit of tartar, 
with hypertrophy of the mucous membrane and gums. 

2. The development of the alveolar process depends on the use or 
disuse of the teeth. When the bite is too close in the posterior 
portion of the arches, an effort is often made by Nature to correct 
this by lengthening ^the process in the anterior part. Cases of ante- 
rior protrusion afford study of these conditions. When forced to 



INTRODUCTION. 15 

perform an abnormal function in these cases excessive development 
results. 

3. 'Not only does tlie alveolar process lengthen when not in use, 
but individual teeth elongate as well when deprived of their an- 
tagonists. 

4. Nowhere does interrupted function produce more mischief than 
in the derangement of articulation. The function of every indi- 
vidual tooth is indicated by its form. This shows that it should 
touch at certain points and antagonize at others. There is a certain 
degree of motion perceptible only by its effects. When the support 
of a tooth is withdrawn by the extraction of its neighbor, this 
motion is no longer sufficiently restricted, and there is more or less 
migration or tipping. The basilar ridges of the anterior teeth, and 
the cusps of the posterior, are resting-places for their antagonists. 
Let this support be taken from one or more teeth, and their function 
is destroyed in part and their health impaired. 

The portion of the book devoted to treatment is carried out on 
the same plan as the first part, i. e., general principles are laid down 
rather than a great many details. The mechanical principles upon 
which the regulating appliances are based are described, so that the 
power and limitations of each are understood. The hap-hazard 
method of employing the same means for the correction of what 
appears to be the same case is discouraged, inasmuch as the re- 
sistance offered is an unknown quantity in every case, and cannot 
be accurately determined beforehand. Great intelligence and 
an exact knowledge of every mechanism is, therefore, of im- 
portance. Simplicity of construction is advocated for obvious reasons, 
as some simple appliances, easily manipulated, may serve for a 
number of different purposes when their range of usefulness is 
understood. 

The author has endeavored to aid the student in becoming a close 
and accurate observer, and to form correct conclusions, close obser- 
vations and correct methods of thought being the means of scientihe 



16 INTRODUCTION. 

progress. When these habits are once established every denture 
that comes under the practitioner's notice will afford points of inter- 
est ; he will not only see the tooth upon which he may be operating^ 
but will notice points in the articulation which will furnish him with 
excellent material for study. 

It is a deplorable fact that what is called scientific research is 
frequently of no value whatever, but is recorded and read by a 
large and credulous portion of the profession. Generalizations 
based on the observations of a few cases are taken for general laws, 
and so recorded. The mere accompaniment of a phenomenon is 
taken for a cause ; the opinion of a layman, who cannot possibly 
have a knowledge of the case, is recorded as a fact. These asser- 
tions are easily verified. However successful we have been in this 
country, we have much to learn from our European brethren in this 
respect, — a number of years' careful preparation for work, and the 
collection of sufficient data before these are embodied in print. This 
will come in time. We shall learn that four years of study are 
more likely to produce satisfactory results than two, — that time is a 
necessary element of success. This will do away with hasty conclu- 
sions and methods of reasoning that do not deserve the name. 
When we have attained comprehension of the utility of thorough- 
ness there will be a greater respect for knowledge among ourselves, 
and with this will come the respect of the public for our profession ; 
for how^ever easily the public appears to be duped, it is keen-eyed in 
the long run and gives honor to whom honor is due. With the 
strides of progress that we are making in many respects, and our 
material gains, come new requirements. The dentist of fifty years 
ago, who honestly did his work as best he knew, and by virtue of 
conscientious efforts produced results that have stood the test of years, 
does not meet the requirements of to-day. There is now a demand 
for more breadth of scientific culture, and more of that comprehen- 
sive knowledge without which good judgment is impossible. 



IRREGULARITIES 



OF 



THE TEETH 



PAKT I 



CHAPTER I. 

HISTORICAL SKETCH OF THEORIES REGARDING THE ETIOLOGY 
OF IRREGULARITIES OF THE MAXILLA AND TEETH. 

SUPEENUMEEAEY TEETH. 

Hippocrates, who lived about 500 b.c., was the first to study 
human teeth, and laid down the dictum, " The more teeth the longer 
life." *' The fewer teeth the shorter life," said Aristotle about one 
hundred years later. 

In 1618 Hilkiah Crooke published a work Mcxpoxo(T/uLoypa<pta, in 
which he gives the views of the best anatomists. In this it is ob- 
served that there are sometimes four and sometimes five grinders. 

On second Dentition the author says : *' The shearing (i.e., in- 
cisors) teeth, when they do break forth, do thrust the first shearers 
out before them and issue betwixt the first two, the second and the 
dog tooth that is next unto them. But if the former teeth will not 
fall or be not pulled out, or if the latter issue before the first falb 
then the latter make their way through new sockets and turn in 
the upper jaw outward, in the lower jaw inward, so that there 
seemed to arise a new row of teeth, and this indeed hath deceived 
many historians and anatomists also." 

2 17 



18 IRREGULARITIES OF THE TEETH. 

Barth Ruspini, in 1750, says: "All the teeth that exceed thirty- 
two may be regarded as supernumerary." He attributes irregular- 
ity of canines and incisors to extreme narrowness of the jaws. 

Robert Blake, 'in a translation of his inaugural Dissertation, pub- 
lished in 1798, speaks of supernumerary and inverted teeth. 

Joseph Harris, "A Familiar Treatise on the Teeth," 1830: 
" Irregularity is due to supernumerary teeth." 

John Winckworth, 1831, speaks of supernumerary teeth causing 
irregularity. 

THUMB-SUCKING, AND SIMILAE CAUSES. 

J. Imrie, Parents' Dental Guide, 1834 : " Irregularity is due to 
want of development of jaw-bones, intemperance of various kinds 
combined with artificial modes of living introduced by civilization, 
and sudden transition from heat to cold to which the teeth are 
subject — all these have a tendency to prevent development of the 
bones. Rabbit mouth is due to keeping the thumb in the mouth 
for hours, after going to sleep. Underhung jaw is due to * sucking 
the tongue,' by throwing the under jaw-bone from its articulation. 
A similar state of the teeth and jaw-bones is induced when attempts 
are made by the inexperienced to regulate them by the extraction 
of teeth in the upper jaw and neglecting to remove an equal num- 
ber in the lower." 

J. Lefoulon, " A New Treatise on Theory and Practice of Dental 
Surgery " (translated from the French by Thomas Bond, 1844): 
'' Among the causes of Dental Irregularity we may regard as the 
most frequent, the neglect of proper supervision of second Dentition. 
Very often the temporary teeth are too precipitately removed and 
again the opposite error is committed of suffering them to remain 
even after the permanent have partly appeared. There results 
from this an error of relation between the development of the pala- 
tine arch and the superior alveolar border, or of the two arches at 
once, relatively to the size of the teeth. Another cause is the bad 
habit of permitting children to suck their thumbs and continually 
to be putting their hands into their mouths. Another is the fre- 
quently repeated action of the tongue in the pronunciation of cer- 
tain syllables called lingual, in which that organ, striking against 
the anterior superior teeth gives rise to anterior obliquity of the 
superior arch. We may remark that this deformity is very frequent 



THUMB-SUCKING AND SIMILAR CAUSES. 19 

with the English, resultiog from the pronunciation of lingual 
syllables." 

About the same year Dr. Thos. Ballard claimed certain pecu- 
liarities, such as serrated teeth and projecting jaws, to be the result 
of fruitless sucking. 

Stockton's Dental Intelligencer^ 1845, from the ''Forceps:" 
" The comparative ease by which, with pressure, the incisors or 
bicuspids may be made to alter their position, would naturally 
suggest the idea that the tongue, lips or cheek might, in some 
measure, influence their original direction ; but as these are pressed 
by every one, while certain individuals only have their teeth un- 
evenly arranged, we may look for some other accessory ; and this 
may be found in the form of the palate, certain peculiarities of which 
are found in connection with similar forms of the dental arch. 
Irregularity of position is almost exclusively confined to anterior 
five teeth on each side of the medial line, brought about by pres- 
sure of tongue upon hard palate in sucking or mastication." 

Nasmyth's " Researches on Development, Structure and Diseases 
of the Teeth," 1845 : *' Projecting upper jaw is often the result of 
a habit of sucking the tongue or finger in infancy. But both pro- 
jecting upper and projecting lower jaw arise from an arrest of 
development in the jaw when expansion of the arch is deficient." 
He also states that we find the prominent mouth in uncivilized 
races. 

The theory that irregularity may be due to thumb-sucking, so 
much made of in modern times, was mentioned by different writers 
during the last forty years. Among these H. D. Ross speaks of 
it in 1853. At the same time he remarks, what must have been 
observed as soon as there was an attempt at correction, that there is 
greater difficulty in keeping teeth in position after they are moved 
than in moving them. 

A. A. De Lessert, 1873, attributes deformity to fruitless sucking 
and to enlarged tonsils, which necessitate an open mouth. 

Thomas Salter, " Dental Surgery," 1874, attributes irregularity 
to hypertrophy of tongue and thumb-sucking. 

J. W. White, 1879, says that the protrusion of lower jaw is due 
to the habit of sucking the first and second fingers ; the weight of 
the hand and arm causing a protrusion of lower jaw and teeth. 

Mr. Francis Fox, 'irregularity of Teeth and their Surgical 



20 IRREGULARITIES OF THE TEETH. 

Treatment," 1880: Causes of irregularity are "want of proportion 
in the size of the teeth and jaw-bones or prolonged retention of 
temporary teeth, supernumerary teeth, habit of thumb-sucking or 
undue pressure from an hypertrophied tongue, or heredity." 

RETENTION OF TEMPORAEY TEETH. 

Thomas Berdmore in 1768 says that the cause of supernumerary 
teeth or a double row of teeth is due to the fact that the milk-teeth 
are never shed, notwithstanding the fact that the permanent teeth 
appear. Irregularity of teeth is due to the resistance offered the 
permanent by the temporary, which also occasions snaggled, rough 
and indented teeth. 

Joseph Fox, "Natural History of Human Teeth," in 1803: 
" Most frequent cause of irregularity is a want of simultaneous action 
between the increase of the permanent teeth and the decrease of 
the temporary ones by the absorption of their fangs, most com- 
monly occasioned by the resistance of the nearest temporary teeth ; 
also from the fact that the permanent teeth are too large for the 
space occupied by the temporary. The growth of more teeth than 
the natural number frequently occurs, and is always the cause of 
great irregularity of the teeth." 

Joseph Murphy, in " Natural History of the Human Teeth," 
speaks of irregularity due chiefly to the first teeth not having been 
shed in time. 

Benjamin James, in " A Treatise on the Management of the 
Teeth," 1814, says: "With proper attention paid to the removal of 
the first set of teeth, the regularity of the second set may be antici- 
pated." 

Parmly, in " Lectures on Natural History and Management of 
the Teeth," 1820, states that : " Want of attention during the period 
of shedding the first set of teeth is great cause why irregularity of 
the teeth and consequent deformity of the mouth are apt to take 
place." " When the permanent teeth are large and growth of the 
jaw does not proceed in a corresponding proportion, they are found 
to crowd and overlap each other." 

G. Waite, "Surgeon-Dentists' Anatomical and Physiological 
Manual," 1826 : *' Irregularities of the teeth are mostly occasioned 
by the pressure of the temporary upon the permanent, throwing them 
in a wrong direction." 



SLEEPING WITH THE MOUTH OPEN. 21 

a S. Fitch, " System of Dental Surgery," 1835 : " Irregularity is 
due to want of simultaneous action between the increase of the per- 
manent teeth and the decrease of the temporary by the absorption 
of their fangs ; to the greater size of the permanent in comparison 
with the temporary," 

''Treatise on Diseases of the Mouth," by J. B. Garriot, 1843, 
translated by J. B. Savier : " Deciduous teeth, by their presence, 
often prevent the permanent teeth from arranging themselves in 
their proper position. Should we neglect to extract the milk-teeth 
and other measures capable of favoring a good arrangement of the 
permanent teeth, deformity — often very serious — may ensue." 

GKOWTH OF MAXILLA. 

Hunter, in 1771, in "Natural History of the Teeth," speaks of 
supernumerary teeth ; he states that the jaw grows at the posterior 
edgesy and that irregularity is often due to the ten anterior permanent 
teeth being larger than the ten anterior temporary teeth, while the 
corresponding part of the jaw^ is of the same size ; therefore in such 
cases the second set is obliged to stand very irregularly." 

G. M. Humphrey made observations on the mode of growth 
of the lower jaw. He claims there is no interstitial growth. The 
five permanent front teeth occupy exactly the same position through- 
out life, and all other additional teeth are added to the hinder end 
of the jaw. This hind end is enlarged by the absorption of the an- 
terior coronoid edge and the deposition on the posterior edge. When 
the molars are first formed they are under the coronoid process, and 
are subsequently exposed — theories proven by experiments on young 
pigs. 

SLEEPING WITH THE MOUTH OPEN. 

Tomes, in "Dental Surgery," 1859 and 1870, mentions the fact 
that deformity is caused by sleeping with the mouth open. He 
makes no mention in edition of 1848. 

W. Matthews, 1880, in paper read before Students' Society of the 
Dental Hospital of London, attributes irregularity to enlarged ton- 
sils, which necessitate breathing being carried on with open mouth ; 
also to heredity, maxillae being smaller in proportion than the teeth, 
which is due to the lessened work of maxillae and teeth by civilized 
races; also cross-breeding and thumb and lip-sucking, retarded 
shedding of temporary teeth and too early extraction of first perma- 



22 IRREGULARITIES OF THE TEETH. 

nent molars. " Congenital V-shaped jaw is that form in which, pre- 
vious to birth, the form of the upper maxillse is such that its cornua 
do not diverge posteriorly, but are parallel, and as that portion of 
the jaw already formed never changes its form, the newly-added 
parts will pass off in divergent lines, forming an angle with that 
previously existing, in order to correspond with the increasing width 
of the base of the skull." 

PREMATUEE EXTRACTION OF TEMPORARY TEETH. 

L. Koecker, 1826 : *' The deformity which consists in shutting 
the under incisors and cuspidati over the upper, has been produced 
by the injudicious extraction of some of the teeth of the upper jaw, 
without taking proper care to secure a due proportion between the 
upper and under jaws." We have irregularity also when the tempo- 
rary teeth are not extracted in time, and when we have too long 
persistence of temporary. 

Thomas Bell, " Anatomy, Physiology and Diseases of the Teeth," 
1829 : " Most unusual cause of permanent irregularity is the actual 
want of sufficient room in the jaw of the ultimate regular arrange- 
ment of the teeth, and this may occur from disproportionate narrow- 
ness of the jaw (whether from original formation or produced by too 
early removal of temporary teeth) or from preternatural size of the 
permanent teeth." 

Joseph Scott, "Art of Preventing Loss of Teeth," 1831 : " Irreg- 
ularities arise from — first, a natural want of sufficient expansion in 
the jaw-bone at the time of their protrusion ; second from not ex- 
tracting the temporary teeth at the proper time ; third, by too early 
an extraction of the temporary teeth ; fourth, from supernumerary 
teeth." 

John Nicholles, "Teeth, in Relation to Beauty, Voice and 
Health" 1833 : " Deformity may be due to too long persistence of 
temporary teeth, or may arise from some malformation of the teeth 
or jaw, entirely beyond the previous control of the dentist." 

R. Maclean, " Treatise on Human Teeth," 1836 : " Due expan- 
sion of the jaw is prevented by premature extraction of the tem- 
porary teeth, the permanent thereby becoming crowded and ir- 
regular." 

E. Spooner, " Popular Treatise on the Teeth," 1836 : " First and 
most frequent cause of irregularity is a want of simultaneous action 



PREMATURE EXTRACTION OF TEMPORARY TEETH. 23 

between the protrusion of the permanent teeth and absorption 
of the fangs of the temporary. Second cause is a narrowness of the 
maxillary arch or a want of proportion between the extent of it and 
the size of the teeth. Another cause is by the premature extraction 
of the temporary teeth ; the jaw is liable to contraction, and when 
the permanent teeth come in there will not be room in the jaw for 
them. Irregularity is also due to supernumerary teeth." 

Wm. Thornton, *'A Popular Treatise on the Preservation of 
Teeth and Gums," 1836 : " Irregularities of the teeth proceed from 
three causes, — first, from a natural want of sufficient expansion 
in the jaw-bones at the time of the protrusion of the teeth ; second, 
not extracting the temporary teeth at the proper time ; third, too 
early an extraction of the temporary teeth." 

Mortimer, 1836 : '.' Irregularities arise from natural or accidental 
causes." 

Natural causes arise from a bad conformation of the jaw, so that 
several teeth are over each other ; from the teeth being much larger 
than they should be ; from coming out of order and place ; from 
teeth growing out of the palate or projecting into the mouth. 

" Accidental causes arise from neglect or ignorance in removing 
milk-teeth too soon ; when the second teeth from some internal 
cause take a direction inwards or outwards ; underhung jaw arises 
from making faces." 

Charles De Loude, " Surgical, Operative and Mechanical Dentis- 
try," 1840; "Irregularity is due to supernumerary teeth, to second 
teeth being too large and maxillary arch too narrow, and to too early 
extraction and too long persistence of temporary teeth, and to shape 
of the maxillary arch, and to heredity, where the child inherits the 
jaw of one parent and the teeth of the other." 

Sam Ghimes, 1843, speaks of the underhung jaw being due to the 
upper incisors extending inwards, and on closing the mouth they 
come in contact with the lower ; this makes the child inclined to 
protrude the lower jaw% which finally becomes habitual, and promotes 
the increase in the length of the jaw itself 

Early French writings contain little or nothing on the subject. In 
a German work — " Nessel's Compendium der Zahnheilkunde," 
1856— the cause of irregularity is attributed to the premature ex- 
tractions of temporary teeth. The alveoli, it is stated, form a bone- 
scar in such cases, which is an obstacle to the advancement of the 



24 IRREGUI.ARITIES OF THE TEETH. 

permanent teeth. In consequence, it is claimed, the permanent teeth 
come before the jaw is sufficiently expanded to receive them. 

DEVELOPMENT OF SPHENOID. 

J. L. Down, " Kelation of Teeth and Mouth to Mental Develop- 
ment," 1871, wrote: "Excessive vaulting of palate, due to arrest of 
development of the sphenoid or defective growth of vomer. The de- 
fects are developmental defects, and betoken a cause long anterior to 
the time when sucking the thumb is practiced, unless that habit be 
an intra-uterine one." 

Mr. Oakley Coles, " Origin and Treatment of Certain Irregu- 
larities of the Teeth," 1881, before International Medical Congress, 
said his observations in regard to intermaxillary prognathism were 
based on the authority of Mr. Hilton. 

Dr. Oakley Coles expressed the opinion, held by others about the 
same time, that the best types of English jaw give an equilateral 
triangle. He applied Greek names to the different classes into 
which he divided various forms of arches ; he gave no basis for his 
classification except that of form. He attributed intermaxillary 
prognathism to a force originating in the sphenoid bones and acting 
on the intermaxillary bone, and held that premature ossification of 
the sutures operates powerfully in the production of oral deformity. 

ATTEIBUTED TO CIVILIZATION. 

J. P. Clark, " A New System of Treating Human Teeth," 1829 : 
** Irregularity may arise from too premature extraction of tempo- 
rary teeth. Disproportion between the teeth and the jaws may be 
occasioned by a natural conformation of the parts or may be the 
unnoticed effect of accident. For we seldom find any such dispro- 
portion and consequent irregularity in the teeth of men and ani- 
mals in a wild state." 

J. L. Levison, in " Jaws and Teeth of Semi-barbarous Men," 
1852: " The jaws of civilized men are more contracted than those 
of semi-barbarous races, and this is the result of the direct violation 
of the Creator's laws, who willed that the brain and nervous sys- 
tem of the growing child should not be overtaxed, and that the 
dental process of attempting to build up the organic instruments 
and cultivate the mental faculties at the same time is a matter 
almost impossible to accomplish." 



CONSTITUTIONAI. CAUSES. 26 

In British Journal of Dental Science of 1«64 an extract of George 
Catlin's " Breath of Life " is given. In this he states that malfor- 
mations of teeth are due to keeping the mouth open, as civilized 
man is the only animal who keeps his mouth open during sleep. 

Mr. Mummery and Mr. Nichols made extensive observations in 
I860 on the teeth of savage races. They report that irregularities of 
the teeth and contracted jaws were rare. Mr. Nichols found but 
one case of slight irregularity among the thousands of Indians and 
Chinese which he examined. Messrs. Coleman and Cartwright 
examined a large number of skulls in the crypt of Hythe Church 
in Kent. These were very old, though their history is not known 
definitely. All of them had well-developed jaws and alveolar arches, 
and the teeth that were still present were remarkably regular. 

About 1864 Mr. Samuel Cartwright read an able paper before 
the Odontological Society of Great Britain. In this he expresses 
his views that irregularities result from selective breeding; that 
they are both congenital and hereditary ; that there is very little 
increase in the anterior part of the jaw after eight or ten years; 
that if the temporary teeth were to remain, the jaws would not 
change from those of childhood ; that in all cases of irregularity 
the maxillae are more or less altered in proportion of development, 
whilst the teeth maintain, in regard to their size, an average devel- 
opment. 

Mr. Hepburn, in " Irregularities of Teeth and their Treatment," 
1870, says: ** Contracted maxillae and alveoli are the result of arti- 
ficial life and other causes attendant on civilization. Ethnologists 
aflirm that with the advance of civilization, there is decrease in the 
size of the facial and maxillary bones." Deformity is also attrib- 
uted to cross-breeding. 

Among comparatively recent works on irregularities, that by 
Kingsley on " Oral Deformities " is one of the most important. He 
attributes irregularities chiefly to premature extraction of tempo- 
rary teeth, intermarriage between persons of diflPerent nationalities, 
hereditary and disturbed innervation. 

CONSTITUTIONAL CAUSES.* 

John Fuller, 1810, attributes irregularity to too long persistence 
of temporary teeth ; he also says that the upper jaw is too small for 

* This term, used by the author, is explained in chapter III. 



26 IRRBGUI.ARITIES OF THE TKKTH. 

the permanent teeth, which fact often occasions irregularity. "Some 
children have the habit of projecting the under jaw forward^ and, 
of course, shutting one or more of the under front teeth beyond the 
upper, which soon becomes permanent." 

Mr. Sigmond, in " Treatise on Diseases and Irregularities of the 
Teeth and Gums," 1825, attributes irregularities to — 1. Natural ; 
2. Accidental causes. "Natural, (1) when they result from the 
jaw not expanding sufficiently to allow the teeth to form a regular 
circle ; (2) when they are larger than the ordinary dimensions ; (3) 
when they do not appear in their proper order and place. Acci- 
dental, when caused by negligence or improper treatment at the 
time of their growth." 

Andrew Clark, " Practical Directions for Preserving the Teeth," 
1825 : " That irregularity of the teeth is occasioned by want of 
room in the jaw, and not from any effect that the first set produce 
upon them, is evident because, in all cases of irregularity, we find 
that really there is not room to admit of placing all the teeth prop- 
erly." 

William Robertson, "A Practical Treatise on the Human Teeth," 
1841, says: "Deformity is due to inheriting the contracted jaw of 
one parent and the large teeth of the other." 

Savier's translation of F. Maury's "Dental Art" 1842: ^'Prom- 
inence of upper jaw is due to narrowness of the arch ; recession, 
due to the anterior teeth." 

C. A. Harris, " Principles and Practice of Dental Surgery," 
1845 : " An infringement of laws of growth or disturbance of the 
functional operation of any of the organs of the face or head may 
determine an improper development of the jaws and a bad arrange- 
ment of the teeth." He also mentions supernumerary teeth and 
irregular individual teeth ; he attributes irregularity of the teeth to 
the narrowness of the maxillary arch, and sometimes to the pres- 
ence of temporary teeth. 

Arthur, " A Popular Treatise on Diseases of the Teeth," 1845 : 
" Irregularities of the teeth may proceed, amongst others, from 
three principal causes : First, the presence of a greater number of 
teeth in the mouth than is natural ; second, a deficiency of space in 
the jaws; third, a wrong direction given to one or more at the 
time they make their appearance. A deficiency of space may arise 
from a contraction of the jaws in consequence of the too early ex- 



CONSTITUTIONAL CAUSES. 27 

traction of the temporary teeth ; from some original malformation 
of the jaws, or from a great excess in size of the second set over the 
first." 

W. K. Brideman, 1845, "On Causes of Irregularity of the 
Teeth," denies the aid of the tongue, lips or cheek in influencing 
the teeth from original direction ; but attributes it to shape of 
the jaw. 

Sam Harbert, 1847 : Irregularities of teeth are due to prema- 
ture extraction of deciduous teeth and protrusion of permanent 
before the absorption of a deciduous fang. A projection of lower 
jaw is attributable to neglect in second dentition ; generally it is 
supposed to be due to elongation of the jaw, which is almost always 
an error. When the dental arch becomes contracted at the medial 
line, giving to the mouth a pointed appearance, it is often the 
result of premature extraction of certain of the temporary teeth. 
'• Practical Treatise on the Operations of Surgical and Mechanical 
Dentistry." 

Alfred Canton, 1851, " Teeth and their Preservation : " " Irregu- 
larity of teeth, as regards their shape, position, direction, crowded 
condition, etc., are met with more frequently than is supposed to 
be the case. Causes are chiefly mechanical, depending either on the 
non-increase in size of the jaw in proportion to the growth of the 
teeth to be contained in the alveolar arch ; on the position of the 
permanent teeth with reference to the fangs of their predecessors, 
and lastly, on the increase in size of one jaw in preference to the 
other." 

''Treatise on Second Dentition," by C. F. Delabarre, translated 
for American Journal of Dental Science : " Malconformation of 
denture may be occasioned, first, by a defect in the conformation 
of the jaw ; second, by the simple want of their development de- 
pending upon the health of the individual ; third, by an excess in 
the development of all the teeth, though the jaws are in other 
respects well formed ; fourth, by rapid development of the dentition 
of one set and delay in that of the other ; fifth, finally, by the too 
great size of the teeth of one jaw, which do not harmonize with 
those that are opposite." "Some forms of defective palatine 
arches are hereditary." 

J. R. Duval, " The Youth's Dentist : " " In a projecting chin the 
alveolar arch, in which the incisors and canines are placed, has 



28 IRREGULARITIES OF THE TEETH. 

taken a development upon a parabolic line, greater and more 
prominent than that presented by the body of the bone ; this differs 
very little from a similar one in upper jaw, which projects over the 
lower. Upon attention to shedding of temporary teeth depends the 
fine arrangement of the lower." 

Dr. Gunnell, in American Journal of Dental Science, states that 
protrusion of lower jaw is in many cases hereditary ; but often is 
brought about in this way — the incisors of the lower jaw are cut 
first, and when the upper ones make their appearance the lower 
have nearly arrived at their full growth. In closing the mouth 
they come in contact with the gum on the inside of the upper in- 
cisors, and for relief the lower jaw is thrust out, which soon becomes 
permanent. 

Samuel Cartwright, Jr, in lecture delivered before King's Col- 
lege, reported in British Journal of Dental Science, in June, 
1857, says, the '^ irregularities of permanent teeth are due, first, to 
non-absorption of the roots of temporary teeth in proportion to the 
rise of those of replacement ; second, the great difference which 
commonly exists in the size of the new teeth as compared with 
those of the first set ; third, contraction of the arches of the jaws 
and other malformations of maxillary and palate bones, originating 
in hereditary, congenital and other causes." 

A. A. Blount, " Orthodontia," 1866 ; *' Remote causes which 
produce irregularity will be found in the commingling of all 
nations, with national and individual characteristics. Most fre- 
quent causes are the result of accident, indiscriminate extraction 
of the deciduous teeth and too early extraction of permanent 
teeth." 

H. Sewell, " Irregularities and Diseases of the Teeth," 1869 : '' Pro- 
trusion of incisors is due apparently to an abnormal development of 
premaxillary bone." Irregularities are due to " retention of tempor- 
ary teeth, causing permanent teeth to assume an unnatural position, 
also to malformation of jaw, which are usually congenital and at 
the same time hereditary ; may, however, be due to injury or other 
accidental causes." 

WANT OF PROPORTION BETWEEN JAWS AND TEETH. 

David Jobson, "On the Teeth," 1834: " Irregularity is due to 
smallness of maxillary arch and great size of permanent teeth and 



WANT OF PROPORTION BETWEEN JAWS AND TEETH. 29 

their situation, part on inner and of others on outer side of tem- 
porary teeth." 

John Mallan, " Practical Observations on Physiology and Diseases 
of the Teeth," 1835 : '* Now the adult teeth being larger as well as 
more numerous than the milk teeth, it is obvious that they require 
a great deal more room, and when the absorption of the latter does 
not progress equally with the growth of the former, the new teeth 
are crowded up and are apt to be forced out of their natural posi- 
tion by the resistance of the old. Again, if the permanent prove, 
as they sometimes do, disproportionately large in comparison with 
their predecessors, the jaw may not be sufficiently extended to 
admit of their being arranged in regular order, in which case some 
overlap the others and considerable deformity is occasioned." 

Paul Goddard, "Anatomy, Physiology and Pathology of the 
Teeth," 1844: "Most prolific cause of irregularity is the want of 
room in the dental arches — this arises sometimes from a congenital 
defect, but more commonly from early decay and loss of the tem- 
porary teeth, which failing to keep up the alveoli, enables the jaw 
to contract and thus afford too little room for the permanent set." 



CHAPTER II. 
THE ALVEOLAE PKOCESS. 

The alveolar processes are situated upon the superior border of 
the inferior maxilla and upon the inferior border of the superior 
maxilla. These bones are considered a part of the maxillary bones, 
and are so described by anatomists. They should, however, be con- 
sidered and described as practically separate and distinct bones. 
Their structure and functions differ so completely from the structure 
and functions of the maxillary bones that there is little or no simi- 
larity between them. The superior and inferior maxillae are (unlike 
the alveolar processes) composed of hard, compact bone-structure. 
The large, powerful muscles attached to them would indicate that 
powerful work is to be accomplished, and when fully developed they 
retain their full size through life. The alveolar processes are com- 
posed of soft and spongy bone of a relatively cancellous structure. 
As early as the eleventh week of intra-uterine life, calcification 
of the deciduous teeth commences, and by the twentieth week cal- 
cific material is 'quite abundantly deposited. Ossification is also 
rapidly progressing about the dental follicles. At birth the 
sacs are nearly or quite enclosed in their soft bony crypts, and the 
crowns of the teeth upon their outer surface are composed of enamel, 
which is dense and hard. 

The alveolar process, being soft and spongy, molds itself about the 
sacs containing the crowns of the teeth and about their roots after 
their eruption, regardless of their position in the jaw. While the 
alveolar processes have grown rapidly, they have, up to this time, 
developed only sufficiently to cover and protect the follicles while 
calcification proceeds. When the crowns have become calcified and 
the roots have begun to take in their calcific material, absorption 
of the borders of the processes takes place in the order of the 
eruption of the teeth. When the teeth have erupted, the alveolar 
process develops with the teeth until they attain the depth of the 
roots of the teeth, which extend in most instances into the superior 
maxillary bone in the anterior part of the mouth at least. The 
30 



THE AI.VEOI.AR PROCESS. 31 

depth to which they penetrate the bone differs in different mouths. 
The incisive fossa, the canine eminence and the canine fossa give evi- 
dence of this externally. These sockets are lined with exten- 
sions of the process, thus making its upper border irregular. The 
fact that some of the teeth are fixed in the bone as well as in the 
alveolar process makes the correction of some forms of irregularity 
more difficult, for not only does the process have to be reshaped but 
the bone as well. This is quite noticeable in correcting irregularities 
of the teeth in the lower maxilla. The crypts of the permanent 
teeth are located at the apices of the roots of the temporary teeth. 
The permanent teeth have large crowns which touch each other 
forming a line to the posterior part of the jaw. These teeth, as 
they erupt entirely absorb the alveolar process which surrounded the 
temporary teeth, and, as the new set come into place, a new process 
is built up about them for their support. The permanent teeth re- 
quire a deeper alveolar process to support their roots, which are 
much longer than those of the temporary teeth. Hence the differ- 
ence in the depth of the arches of the first and second sets of teeth. 

The alveolar process of each superior maxilla includes the tuber- 
osity, and extends as far forward as the median line of the bone, 
where it articulates with the process upon the opposite side. It is 
narrow in front, and gradually enlarges until it reaches the tuber- 
osity, where it becomes rounded. 

If we examine the two articu- ^^®- 1- 

lated superior maxillary bones 
(Fig. 1), we see that the an- 
terior partis curved, while the 
posterior part gradually di- 
verges from the central line of 
ossification of the maxillary 
bones. The shape varies in 
different individuals. Some 
arches are small and others 
large ; the arch is parabolic in some cases and circular in others. 

The process is composed of two plates of bones, an outer and an 
inner, which are united at intervals by septa of cancellous tissue. 
These form the alveoli for the reception of the roots of the teeth. 
In some cases the buccal surfixces of the roots of healthy teeth ex- 
tend nearly or quite through the outer bony plate. 




32 IRREGULARITIES OF THE TEETH. 

This plate is continuous with the facial and zygomatic surfaces of 
the maxillary bone. The inner plate is thicker and stronger than 
the outer, and is fortified by the palate bones. The external plate 
is irregular upon the outer surface, prominent over the roots of the 
teeth, and depressed between the roots or interspaces. 

The prominence over the canine teeth, called the canine emi- 
nence, is very marked, and decidedly modifies the expression of the 
face. The sockets of the central incisors are conical and round, 
those of the lateral incisors conical and slightly flattened upon 
their mesial and distal surfaces, and not so large as the central 
sockets. 

The pit for the cuspid is conical and much larger than any of 
the other sockets. The sockets for the bicuspids are flattened upon 
their anterior and posterior surfaces, and near the apex they are 
frequently bifurcated. The sockets of the molars are large at the 
openings, but at about the middle of their length they are divided 
into three smaller sockets for the reception of the roots. In the 
case of the third molar the number of sockets ranges from one 
large cavity to three or four of smaller size. 

THE INFEKIOE ALVEOLAE PEOCESS. 

The alveolar process of the inferior maxilla extends from the 
ramus of one side to the same point on the other. The outline is 
similar to that of the superior process, the anterior portion being 
much thinner. 

The description given of the structure of the superior process 
will also apply to the inferior. The outer plate of bone opposite 
to the molars and bicuspids is thicker than the inner plate, while 
the inner plate opposite the canines and incisors is thicker than the 
outer. 

The alveoli are arranged along the border of the bone for the 
reception of the roots of the teeth. They correspond in form to 
the roots which they accommodate. The alveoli for the central 
incisors are smaller than those for the lateral. They are conical in 
shape, and flattened upon their mesial and distal surfaces. Those 
for the lateral incisors are larger, and compressed on their mesial 
and distal surfaces. The sockets for the canines (cuspids, or stom- 
ach teeth) are larger, deeper and less compressed than those for the 
incisors. 



THE INFERIOR ALVEOLAR PROCESS. 



33 



The sockets of the bicuspids are considerably flattcDed upon 
their lateral surfaces, and are sometimes divided into two cavities. 
The sockets for the anterior roots of the molars are broad and flat- 
tened laterally, while those for the anterior roots are round. The 
third molar, being naturally of variable form, has sometimes one 
pit, and again three or four. Each alveolar pit or socket is divided 
from its neighbor by a small wall or septum, which is made up of 
cancellated bone, extending about one-eighth of an inch above the 
inner and outer plate. 

The dental septa assist in keeping the teeth firmly in their places. 

It will be observed that the septa are very thin at the margin, 
and gradually increase in width to the middle of the jaw, where 
they become thicker, and are finally lost in the substance of the 
jaw. Some septa are thicker than others, and where two teeth are 
widely separated, the width of the septa naturally corresponds to 
the space between the teeth. 

The sock'ets are lined with a thin plate of compact bony sub- 
stance, extending from the outer and inner plate of the alveolar 
process to the apex, where there are small openings for the entrance 
of nerve and blood-vessels for the nourishment of the teeth. 

This bony plate has upon its inner surface the elastic peridental 




membrane, which acts as a cushion for the teeth, while upon the 
inner surface it is surrounded by spongy bone. 
3 



34 



IRREGULARITIES OF THE TEETH. 



The teeth are held firm in their alveolar sockets by a union 
called gomphosis, which resembles the attachment of a nail in a 
board. Teeth with one conical root, and those with two or more 
perpendicular roots, are retained in position by an exact adaptation 
of the tissues. Teeth having more than one root, and those bent 
or irregular, receive support from all sides by reason of their irregu- 
larity. The teeth are also held in position by the peridental mem- 
branes. Fig. 2 illustrates the position of the teeth in the jaws. 
The peridental membrane lines the alveolus and covers the roots of 
the teeth. It is a fibrous tissue, which admits of a slight motion of 
the teeth, and acts as a cushion to protect the jaws from severe 
blows and concussions while in the act of tearing and grinding food. 

After the removal of the permanent teeth the alveolar process is 
entirely absorbed. Fig. 3 shows how absorption takes place. The 
teeth have all been removed from the superior maxilla, as has also 




the alveolar process. The molars on the lower jaw have been ex- 
tracted and absorption of the alveolar process has resulted, showing 
a marked contrast in connection with the anterior alveolar process, 
which remains intact and holds the teeth firmly in place. Thus it 
will be observed from the changes which occur from the first devel- 
opment of the teeth to their final extraction, that the alveolar pro- 
cess is solely for the purpose of protecting the teeth in their crypts 
during their development and after their eruption. When the tem- 
porary teeth are in place the alveolar process remains unchanged 



THE INFERIOR ALVEOLAR PROCESS. 35 

(except a gradual enlargement in harmony with the growth of the 
maxillary bones) until about the sixth year, when the second set of 
teeth appears. The crowns of the permanent teeth require more 
space than those of the temporary set ; and the alveolar process 
must necessarily enlarge to accommodate them. This enlargement 

Fig. 4. 




of the alveolar process is doubtless caused by the formation of the 
crowns of the permanent teeth before eruption, and to a limited 
extent by the growth of the maxillary bones, which may cease de- 
veloping at any period in the life of the individual, or continue as 
late as the thirty-sixth year. The diameter of the crowns of the 
permanent teeth forming a larger circle than that of the maxillary 
bones, the alveolar process must necessarily increase its diameter. 
It is often forced outside of the superior maxilla by the crowns of 
the permanent teeth crowding and wedging themselves into posi- 
tions anterior to the first permanent molar teeth. This enlargement 
of the alveolar process usually takes place anterior to the first per- 
manent molars. We expect to find the process corresponding in 
size to the jaws. Fig. 4 shows a comparatively small superior 
maxilla, the inferior being much larger. This is the result of ar- 
rested development. To allow for the deficiency in bone-structure 
and allow the upper teeth to extend over the lower, the upper teeth 
have forced the alveolar process forward. The space shows where 
a tooth was extracted after all the teeth were in position. 



36 IRREGULARITIES OF THE TEETH. 

Fig. 8 shows a similar case where all the upper teeth have been 
removed and absorption has entirely obliterated the alveolar pro- 
cess The relations of the superior maxillary bones to the alveolar 
process and teeth on the lower jaw are well illustrated. When the 
alveolar process and teeth were intact they presented an appearance 
like illustration No. 4. 

The position and shape of the processes and their relation to each 
other are governed entirely by the location and size of the teeth and 
roots, and not by the shape of the jaw-bone proper. The dental fol- 
licles containing the crowns may be located upon the outer border of 
the jaw-bone on one side, in which case the alveolar process will be 

Fig 5. 




situated upon the outer border and assume an irregular arch. If 
the crowns of the teeth are located upon the inner border, or if 
one jaw be smaller than the other, the teeth will articulate and the 
process will form a smaller circle than the jaw-bone proper. Such 
a case is illustrated in Fig 5. The superior maxilla is much larger 
than the inferior, and, as a result, the articulation of the teeth and 
the muscles of the cheeks and lips have carried the teeth and 
alveolar process on the upper jaw inward. The teeth on the lower 
jaw are regular and appear to have sufficient room, while those 
upon the upper jaw are crowded and overlap each other. The teeth 
on the left side of the upper jaw are more regular than those on the 
right side. Upon examining the mouth or model, the arch on the 
left side will be found full and regular, while the arch upon the 
right side has a perfect semi V-shape. 

The alveolar process on the right side extends considerably over 



THE INFERIOR ALVEOLAR PROCESS. 37 

the border of the maxillary bone, and the teeth (especially the 
ciis id) have taken quite an incline in order to articulate with the 
teeth upon the lower jaw, thus crowding the alveolar process to the 
inner border of the maxillary bones. 

The process is solely for retaining the teeth, and if for any reason 
the dental follicles should not be present and the tooth should not 
erupt, or if it should have been extracted early, the process would 
not be developed at that point. In my collection of models may be 
seen cases of arrested development of the alveolar process, caused by 
the lack of bicuspid and lateral incisor germs, and by the extraction 
of the deciduous and permanent teeth. 

If one or more teeth should not antagonize, the alveolar process 
would extend beyond the natural border, carrying the teeth with it. 
A marked illustration of this is seen where the molars are decayed 
to the gum and the roots remain. The vascularity of the process is 
such that its development results. Excessive development of the 

Fia. 6. 




alveolar process is frequently observed by every practitioner in con- 
nection with the anterior inferior teeth. When the articulation is 
normal, occlusion of these teeth never takes place. We frequently 
find (especially in patients from ten to sixteen years of age) these 
teeth extending to and occluding with the mucous membrane of the 
hard palate, making one of the most difficult forms of irregularities 
to correct. Such a case is illustrated in Fig. 6. This model is taken 
from the jaw of a person thirty-seven years of age, but I venture the 
statement that this excessive development took place between the 
ages often and sixteen, because at that period the vascularity of the 
tissues is more vigorous and the development of the process more 



38 IRREGULARITIES OF THE TEETH. 

formative than at any period subsequent to the development of the 
first permanent teeth. 

I recall a case in practice in which the incisors and cuspids, 
together with their alveolar process, are situated upon the external 
surface, while the bicuspids, molars and their alveolar process are 
located upon the inner border of the jaw. Another case is one 
in which the alveolar process failed to cover the roots of the bicus- 
pids and molars upon the outer surface, the teeth having forced 
themselves into a larger circle through the alveolar process by the 
contact of the crowns. The roots in this case can be easily outlined 
by the finger through the mucous membrane, the outer plate of the 
alveolar process barely, if at all, covering them. Mr. Tomes men- 
tions and illustrates a case in a late work of faulty development of 
the outer plate of the alveolar process exposing the crowns of all 
the temporary teeth. The case was a child who had suffered from 
hydrocephalus. I have a number of models showing the anterior 
alveolar process projecting beyond the normal position by the for- 
ward movement of the molars. This may be due to a natural 
movement of the molars forward, or the process may be forced 
forward by the improper occlusion of the jaws. The teeth are 
moved from one position to another simply by the force consequent 
upon absorption and deposition of bone. This is noticeable in the 
spaces between the centrals, when the alveolar process develops to 
a larger circle than is necessary to accommodate the teeth. The 
alveolar processes are influenced in one direction or the other by 
the pressure of articulation. This abnormal condition is the result 
of inharmonious development of the jaws. The teeth may come 
together in such a manner as to throw the alveolar processes either 
to the right or left, thus producing a full round arch upon one side 
of the jaws and a perfectly flat or straight arch upon the other. 
(See Fig. 5.) The greatest deformity is that in which the teeth of 
the upper jaw and alveolar process are forced forward, causing a 
protrusion of the anterior superior part of the mouth. Occasionally 
we find both upper and low^er alveolar processes carried forward in 
the same manner. The alveolar process upon the lower jaw is more 
liable to be found upon the inner border of the jaw than is the upper 
alveolar process, as the inferior maxilla is larger and more dense 
than the superior, and when the teeth are once in position upon the 
lower jaw they are not liable to subsequent change. Owing to this 



HYPERTROPHY OF THE ALVEOLAR PROCESS. 39 

fact the teeth of the superior maxilla do not form so great a circle, 
causing the teeth upon the sides of the jaws to conflict and the lower 
teeth and alveolar processes to be carried in, while the anterior teeth 
of the lower jaw are held inside of the superior anterior teeth, thus 
carrying the alveolar process inward. 

The teeth are continually changing their positions in the mouth. 
This is beneficial as often as it is detrimental. That the teeth may per- 
form their full function, they should not only remain firmly fixed 
in the alveolar process, but they should also antagonize. The teeth 
may be compared to the bricks in an arch. Remove a brick and 
the arch falls to pieces. It is frequently found that the teeth do not 
articulate properly, and by cutting away the approximal surfaces a 
better articulation may be secured. When this operation is per- 
formed, the teeth move in their sockets by absorption and deposition 
of bone, demonstrating the fact that the process changes in shape 
and substance. 

HYPEKTKOPHY OF THE ALVEOLAE PROCESS. 

From what has already been said of the vascularity of the alveo- 
lar process, we may expect to find hypertrophy of the tissue ensuing 
from simple irritation of varying degree. The irritation consequent 
upon the eruption of the teeth, together with the excessive blood - 
supply, are both primal causes of over-building of tissue, i.e., hyper- 
plasia. 

The ragged roots of the temporary teeth, produced by absorption, 
the gases from the putrescent pulps, and the pressure of the perma- 
nent crowns against the tissues, produce sufficient stimulation to 
excite physiological action. Tissue-building generally is seen in 
connection with the teeth posterior to the cuspid, rather than with 
the teeth anterior to that tooth. It seems accountable only from 
the fact that the incisors have sharp cutting-edges, the roots of the 
teeth are single and nearly always shed before the permanent teeth 
are in place, and they erupt at an age when there is less vitality. 
Per contra, the crowns of the teeth posterior to the cuspid are broad, 
the roots of the temporary teeth posterior to the cuspids are more 
numerous than those anterior to them, and, with the exception of 
the first permanent molars, they erupt at the age of greatest vital- 
ity. The process becomes unnaturally thick, the bicuspids and 
molars are carried in one direction and another, effecting a variety 



40 



IRREGULARITIES OF THE TEETH. 



of irregularities. A comraon form is shown in Fig. 7. Similar ir- 
regularities are also seen in Cole's " Deformities of the Mouth," 
Figs. 12, 13, and 27; and in Tomes' "Dental Surgery," Fig. 90. 
These deformities all take the contour of the saddle-shaped arch. 
This may be accounted for from the fact that the permanent molars 
being the first teeth to erupt, they become fixed before the deposit 
commences. The crowns of the bicuspids are also held in a small 
circle by the retention of the temporary molars. When these teeth 
do not antagonize, they are liable to be carried inward. 

The cuspids with their long roots meet resistance either in con- 
nection with the teeth adjoining or with those upon the opposite jaw, 

Fig. 7. 




and are thus held in position. It will be observed that, in all of 
these cases, the enlargement seems to be associated with the inner 
plate of the alveolar process. My observation in these cases has 
been that with most of them the inner plate is the part of the alve- 
olar process affected. The outer plate, although quite irregular from 
the arrangement of the teeth, is usually normal in thickness. This 
disparity in the two plates of the alveolar process may be accounted 
for from the fact that the inner plate of the alveolar process possesses 
a large blood-supply, the posterior or descending palatine arteries 
furnishing the ossific material. The author has observed a few cases 
where the hypertrophy has extended to and included the outer plate. 
When the outer plate becomes involved the alveolar process assumes a 



HYPERTROPHY OF THE AI.VEOI.AR PROCESS. 



41 



very thick condition. Occasionally, hypertrophy will affect one side 
only or one distinct locality. Fig. 8 illustrates such a case. In this 



Fig. 8. 




case the enlargement is upon the left side and extends from the first 
bicuspid posterior to, and including, the maxillary tuberosity. In- 
stead of the force being directed inward, as is generally the case, the 
process is forced outward and backward. This enlargement oc- 
curred previous to the development of the second and third 
molars. The alveolar process extends downward and occludes 
with the teeth upon the lower jaw, thus preventing the molars 
from erupting. 



CHAPTER III. 
CONSTITUTIONAL CAUSES. 

Constitutional irregularities of the jaws and teeth are those 
deviations of the normal jaw that are developed with the osseous 
system and are not the result of accident. All constitutional irreg- 
ularities are confined strictly to the jaws, though they may result 
in irregularities of the teeth. 

They have their origin in inherited tendencies, direct or remote, 
resulting in arrested or excessive development, partial or entire, of 
the upper and lower maxillae. Inherited peculiarities do not 
necessarily imply morbid conditions, though most cases of irregulari- 
ties come under this head. Owing to this distinction they naturally 
group themselves under two heads : 

A. Anomalies of jaws in healthy individuals transmitted from gen- 
eration to generation. 

B. Anomalies of jaws that are the result of functional derangement. 
Like all scientific classifications these divisions cannot be kept 

absolutely distinct The first class embraces what we term family 
and race peculiarities, which may have been the product of peculiar- 
ity of function. The monstrously developed angle of the lower 
jaw seen in some persons, the underhung jaw, and the highly de- 
veloped upper maxilla and alveolar process of some Irish and 
Scotch families are examples of this class. 

It would not be reasonable to class all deviations from the ideal 
type under irregularities; otherwise all peculiarities of race or 
nationality would have to be included. 

A. ANOMALIES OF JAWS IN HEALTHY INDIVIDUALS TRANSMITTED 
FROM GENERATION TO GENERATION. 

I. Arrest of Development of the Maxillary Bones due to Kace 
— Crossing, Climate and Soil.* • 

It is a recorded fact that the early races possessed large jaws and 
regular teeth, and this fact has been verified by the examination of 

*Kead before the Indiana State Dental Society, June 25, 1888. 
42 



CONSTITUTIONAL CAUSES. 43 

ancient skulls by Messrs. Cartwright and Coleman, and also by 
John R. Mummery, who has examined the skulls of three thousand 
modern uncivilized people between the years 1864 and 1870. 
Their conclusions were that irregularities of the teeth rarely, if 
ever, occurred among ancient races. More recent examinations by 
Dr. Nichols of the Chinese and Indians, during a stop of twelve 
years on the Pacific Coast and in the Rocky Mountains, show that 
irregularities do not prevail among members of the clannish tribes. 
Among the thousands of Chinese and Indians examined he failed 
to find a case of irregularity of the teeth. "^ 

In 1881 I examined the mouths of more than three hundred 
Chinese without finding a case of irregularity in the shape of the jaws 
and teeth. The jaws of the Chinese are broad across the bicuspid 
and molar regions, and the teeth are very regular. The jaws of the 
African protrude anteriorly, and in this way the teeth find sufficient 
room. By examining the mouths of people living in new countries, 
where the population is made up of immigrants from every country 
w^e shall find some deformities of the jaws and teeth, which will in- 
crease with the growth of the country. 

With these facts before us, what conclusions can we draw ? Every 
nation has its peculiar race of people ; the older the nation, the more 
clannish its people, the more fixed the type, — this type being molded 
after the peculiar characteristics and customs of the people, the 
climate and the topography of the country. The Chinese and 
Africans marry and intermarry among their own people, and the 
progeny are exact types of their ancestry for hundreds of years 
before ; the race remaining excluded from others, and the habits 
and climate unchanged, so long will the characteristic type of a 
nation remain the same. The newer countries, as Germany, France, 
Norway, Sweden, as well as other countries, each have their peculiar 
type of people. Each individual is stamped with characteristics 
proclaiming the country of his birth. The size and shape of the 
head and skeleton, the contour and mold of the body, the manners, 
and all characteristic qualities are transmitted from generation to 
generation The jaws and teeth are alike included in the general 
transmission. But when members of the various nations emigrate 

* Dr. Nichols doubtless refers to saddle and V-shaped jaws and protrusion 
of the upper and lower jaws. 



44 IRREGULARITIES OF THE TEETH. 

and become citizens of a new country, the various influences sur- 
rounding them, of soil and climate and intermarriage, will produce 
in time a people as a whole totally lacking the distinctive features 
of any one race. America fitly expresses this condition : a land 
containing representatives of every country under the sun. The 
Indian and African, perhaps more than other races, illustrate 
this fact. Their progeny, the result of a union of Indian or Negro 
with Americans, do not possess the distinguishing features charac- 
teristic of either of the races, but are recognized as half-breeds, 
octoroons, etc., no longer showing the perfectly symmetrical jaws 
and teeth of the Indian, or the protruding maxilla of the Negro, 
but a smaller jaw, with the face sunken at the alse of the nose. It 
may require generations to stamp out completely the predominating 
features of a race, but time has shown that a decidedly different 
tribe will result. 

"The laws of inheritance," says Kingsley, "confirmed by common 
observation, show how constant is the mingling in the offspring of 
the traits of character and the peculiar features of two diverse 
races brought together in marriage. This mixture, without blend- 
ing or harmonizing, is productive of deformity in character and 
physique. Thus, so far as the jaws and teeth are concerned, they 
may exist in each parent in perfect symmetry : in one parent the 
jaws and teeth are large ; in the other parent both jaws and teeth 
are small; but each in its way is a normal development. If, now, 
the small jaw of one parent and the large teeth of the other appear 
in the offspring, deformity is sure to follow." Benedict declares * 
that abnormality of structure predisposes to disease, and among 
abnormalities of structure he mentions particularly pathological 
length and breadth of the face, pathological relation of the sutures, 
asymmetry and intercalaria. 

The most convincing proof that abnormalities of the jaws are 
mostly due to race mixture is the fact that these abnormalities are 
not found in a pure race, e. g., the Chinese and Negro races. By 
examining the figures of the dolichocephalous (Fig. 9), Sarmatic 
brachycephalous (Fig. 10), and the Turanic or extreme brachyce- 
phalous (Fjg. 11) types, it will be seen at a glance how entirely 
different must be the single measurements, not only of the skull 

* Kranionietrie und Kephalometrie. Wien, 1888. 



CONSTITUTIONAI. CAUSES. 



45 



generally, but of the face, and particularly the superior maxillary 
bones. These types represent, to a greater or less degree, the Ger- 
man, Slav and Finno-Magyar skulls of the present day, though it 
is probable that the differences are not so sharply drawn in living 
specimens. 

Anthropologists agree that racial differences and peculiarities are 
shown more clearly by the skull as a whole than by any other por- 
tion of the skeleton. It is to be supposed, then, that in a mixture 
of two races with important cranial differences, an attempt by na- 
ture to mix the types, without the ability to blend them harmoni- 
ously, must result in an irregularity or abnormality. This argu- 
ment is borne out in almost every respect by the sexual mixtures 



Fig. 9. 



Fig. 11. 




of plants and of the lower animals. In the case of plants, the ab- 
normalities are shown in color, form and structure ; in the case of 
edible plants, by form and structure chiefly, as, for example, the 
fertilization of the watermelon bloom by the pollen of the cucum- 
ber flower ; in the case of animals, by variations in form and 
structure and temperament ; and in man, on account of the pre- 
dominance of the cerebral and nervous functions, and of the chief 
individual differences being found in the face, in variations as to 
form, to a certain extent, temperament and cranial structure. It 
is simply a matter of evolution, of change and reformation of type. 
But in civilized communities the law of survival of the fittest is 
practically annulled. 

Let us suppose, for example, that a person with the form of cra- 
nium shown in Fig. 9 be married to one with the form seen in Fig. 
11. It seems scarcely possible that there could be a perfectly har- 



46 IRREGULARITIES OF THE TEETH. 

raonious blending of the cranial differences in these types, even if 
both parents were in perfect health, and the offspring remain in 
perfect health throughout infancy, which may be said never to ob- 
tain in civilized communities. And what must be the result if 
nature attempt to combine what may be called the intellectual cra- 
nium of Fig. 9 with the animal strength of face and jaws of Fig. 
11 ? Clearly, deformity, or at the least irregularity. Nature could 
never fit the superior maxilla of Fig. 11 into the face of Fig. 9. 
There is no incongruity involved in believing that she would at- 
tempt this. The law of inheritance — call it nature or what else — 
that insists upon perpetuating supernumerary digits and the like, 
would not stop at harmless peculiarities, as is shown by the distinct 
inheritance of disease, such as cancer, tuberculosis, heart-disease, 
etc. Nor is it too much to assert that neuroses, which are distinctly 
hereditable, are, in a large measure, due to abnormalities in the 
conformation of the cranium. 

In investigating the causes giving rise to racial characteristic 
features and to individual deformities, we may gain much valuable 
information from the actions of the conditions of life, and the evo- 
lution of man from the embryonal to the adult state furnishes most 
interesting facts. *' Simple arrest, a slight excess in the evolutive 
phenomena," says Quatrefages, " are, it appears to me, the cause of 
the principal differences which separate, and particularly the two 
extremes, the negro and the white." We need not fall back upon 
a theory of reversion of type. The human foetus furnishes all the 
elements of a human evolution theory. 

Few will deny that what is true of the whole organism is equally 
true of its different parts, organs, functions and energies, and that 
in the formation of a new being the action of heredity is divided 
into as many cases as there are characters to be transmitted. There 
is a tendency on the part of each parent to reproduce itself in the 
child, and consequently there is a constant struggle between the 
two natures in the morphological growth of the child. The more 
dissimilar the parents, the greater the struggle, and the more cer- 
tain the predominance of leading characteristics, and the greater 
the tendency to morphological abnormalities, — arrest or excess. The 
outcome of this struggle, assuming inequality of action on account 
of one parent being stronger, is a number of single combats, in 
which one or the other of the parents is vanquished. 



CONSTITUTIONAL CAUSES.' 47 

In crossing between different races, says Quatrefages, the half- 
breeds possess the characters that in each of them predominate over 
the corresponding characters of the other.''' 

While the general relations of length and breadth in the crania 
of human races are apparent from birth, the studies of Gratiolet go 
to show that dolichocephaly is due to a relative development of 
bones, which varies with age. In the infant it is essentially occip- 
ital, in the child temporal, and in the adult man frontal. Unfor- 
tunately, in this respect, anthropologists have studied the bones of 
the face less closely than those of the skull. In a general way 
faces may be divided into euryopsal and dolichopsal (broad and 
long). For reasons that are apparent, the inferior limit of the face 
should be the alveolar border of the superior maxilla, middle line, 
while the upper limit is the point sus-nasal, — ^the fronto- nasal su- 
ture. The line connecting these points is always less than the bi- 
zygomatic breadth. The product of the length of the face multi- 
plied by 100 and divided by the breadth is known as the facial 
index. Broca show that this index is greatest in the embryo, less 
in a perfect foetus, and constantly diminishes as the body approaches 
its final and definite state ; and from this he concludes that the 
variations seen in the same race may be often referred to an arrest 
of development, or rather to an arrest of evolution. Quatrefages 
regards this as a very correct explanation of one of the distinctive 
features that most clearly distinguishes the black race. It is to be 
remarked that in all races the nasal and orbital indices of the 
woman are greater than those of the man, and consequently the 
woman thus preserves a certain infantile character. 

Now, we know that it is the superior maxillary prognathism of 
the negro that so clearly distinguishes the negro's face from the 
orthognathous face of the white ; and this variety of prognathism 
arises from that portion of the superior maxillary bone situated 
below the nose, and comprising the alveoli of the incisors and 
cuspids. But the degree of prognathism in the individuals of any 
one race is not constant ; there are oscillations of characters that are 
everywhere met with in races not subject to selection with any 
special aim. The prognathism of the negro is evidently an excess 
of development, since it increases with the age of the individual. 

* It must be remembered that every mixed race, when uniform and settled, 
has been able to play the part of a primary race in fresh crossings. 



48 IRRKGUIvARITlES OF THE TEETH. 

More or less essential characters are found in the zygomatic arches, 
the malar bones, and the superior and inferior maxillae ; and in 
reference to a given race, Quatrefages asserts that they acquire a 
value superior to that which they have elsewhere. Such is the slight 
elevation of the palatine vault in the Lapps. 

The existence of a cessation of evolution is again proved by the 
parietal angle, which may be negative in the adult, and is then 
nothing more or less than a persistent foetal or infantile character- 
istic ; for this angle is negative in the foetus and infant in all races. 
The shape and size of the supra-maxillse therefore depend to a great 
extent upon the shape and size of the cranium. 

There are certain characteristics, long supposed to be purely 
racial, that are now definitely known to depend upon climate 
and soil, particularly the former. Such are the statopygia of 
the Bojesman and Houzouana races, which were thought to be 
peculiar to these races until certain women of the Boers, of un- 
doubted Dutch descent, were affected by them. On the other hand 
the fat-tailed sheep of central Asia lost the appendages when the 
Russians removed them from their native country. 

Climate and soil and the conditions of life may modify the bony 
parts to an important extent. Blumenbach showed that there is 
more difference between the head of the domestic pig and that of 
the wild boar than between those of the white and negro races. In 
this connection we are at once reminded of the marked difference 
between the heads and the skeletons of the bull-dog, greyhound and 
spaniel for example. The niata cattle of Buenos Ayres and La 
Plata exhibit characteristics of their own, and not unlike those dis- 
tinguishing the bull-dog from other dogs. " All the forms are short- 
ened and thickened, the head in particular seeming to have experi- 
enced a general movement of concentration. The inferior maxillary 
bone, although itself shortened, so far exceeds the superior in length 
that the animal is unable to browse the trees. The cranium is as 
much deformed as the face ; not only are the forms of the bones 
modified, but also their relations, not one of which, according to 
Professor Owen, has been strictly observed." There is a perfectly 
established race, but it, as are all American cattle, is descended from 
European stock. The wool of sheep is modified to a marked extent 
by change of climate and soil ; and an expert wool man in Chicago 
asserts that he can tell by the feel of the wool from what part of the 
country and particular State it has come. 



CONSTITUTIONAL CAUSES. 49 

The effect of change of climate is seen also in fruits of the soil 
taken from one climate to another. This was first seen in the case 
of the peach, and later in the cases of wheat and tobacco. Tobacco- 
seed brought from North Carolina to Wisconsin and planted soon 
produces an entirely different-looking plant and different grade of 
the tobacco from the parent stock — different in color and proper- 
ties. 

Climate cannot cause these changes alone, however ; in the case 
of plants it is undoubtedly a large factor, — perhaps larger than in 
the cases of the lower animals and men. The structure, appearance, 
color, and other peculiarities of plants are influenced by soil, from 
which they obtain their food directly, and by breeding. The effect 
of close breeding upon plants and fruits, the difference in the results 
when plants are propagated by seeds or by buds and shoots or slips, 
are too well known to require discussion or extended mention. 

In the case of the difference in the texture of the avooI of sheep 
grazed in different localities, it seems that, even with the same fam- 
ily of sheep, food must play as large a part in giving the peculiar 
texture to the wool as climate. In the case of horses of La Ca- 
margue, sheltering and careful feeding of the mares have the effect 
of raising the height of this breed of horses. As regards the human 
family, Durand (de Gros), in confirmation of an observation made 
by Lartet, showed that in the Aveyron the populations of the lime- 
stone cantons are sensibly taller than those of the granite or schistose 
cantons ; and Dr. Albespy stated that liming lands in the non-cal- 
careous portions of this district has raised the height by two, three, 
or even four cm. on the lands where this practice has existed for the 
longest tiaie (Quatrefages). This same effect of liming lands, I am 
told by an army officer born in Maryland, was observed in one of 
the districts of Maryland some years ago. 

That changes of climate and soil do modify races and nations to 
an important extent is shown by the Anglo-American, the Yankee, 
who no longer resembles his ancestors. Andrew Murray, in en- 
deavoring to account for the formation of animal races, said that he 
could not do better than appeal to the condition of mankind in the 
United States. At the second generation of the English Creole in 
America, says Quatrefages, his features present alterations that 
approximate him to the native races. In the face the temporal 
fossse are pronounced, the cheek-bones become prominent, the orbi- 
4 



50 IRREGULARITIES OF THE TEETH. 

tal cavities become hollow, and the lower jaw massive. The negro 
has undergone remarkable changes since being brought into the 
United States, the most remarkable being that his physiognomy 
has altered. " In the space of one hundred and fifty years," says 
Reclus, " they have passed a good fourth of the distance that sepa- 
rates them from the whites, so far as external appearance goes." 
*' We shall have to recognize," says Quatrefages, " that in the 
United States a sub-negro race has been formed, derived from the 
important race." 

In this connection it is a curious and interesting fact that the 
teeth of Scandinavians decay almost immediately after arrival in 
this country, and this is doubtless due to change of climate, soil and 
food. Every race being a resultant whose components are partly 
the species itself, partly the sum of the modifying agencies that 
have produced the deviation from the type, nothing is more in ac- 
cordance with natural laws than that still further modifying causes, 
differing from any that a race has known before, should modify 
types to a very marked degree. The race will retain some of the 
former characteristics, but it will at the same time acquire new 
characteristics Conditions of life and heredity, then, are both 
modifying agents and agents of stabilization, and in either case, says 
Quatrefages, their result is to harmonize organisms with the condi- 
tions of their existence ; and heredity, which is essentially a pre- 
serving agent, becomes an agent of variation when it transmits and 
accumulates the modifying actions of the conditions of life. Those 
who are interested in this subject are advised to read " Animals 
and Plants under Domestication," by Darwin. 

II. Arrest of Developme>'t axd Excessive Growth of the Maxil- 
lary Boxes. 

Excessive growth of bone-tissue is frequently seen in connection 
with the superior and inferior maxillae. It may be a natural growth 
or the result of disease. If the large jaw is naturally so, it will 
develop gradually, and will not attain its full size before the age of 
from twenty-six to thirty-six years. The size of the jaw corresponds 
quite closely to the size of the head, other things being equal, the 
large head containing the large jaw. We occasionally find, how- 
ever, a very small jaw in a very large head, and vice versa. The 
upper jaw is more subject to morbid influences than the lower jaw. 



CONSTITUTION A I. CAUSES. 51 

because of its development in connection with the bones of the head. 
The lower jaw rarely exceeds the average size. It is possible, 
however, by constant use, to increase the size of the jaws, as is shown . 
in acrobats and those who use their jaws in performing various 
feats, like " the man with the iron jaw." The skulls of tobacco- 
chewers, singers, public speakers, and the early races who lived 
upon corn, shells, roots, etc., show that the jaws may be increased, 
or at least favored in their development, in size, by use. If the 
bones at the base of the skull are slow in ossifying, as is sometimes 
the case, the maxillary bone will frequently develop to an unusually 
large size. 

Enlargement of the jaw-bones is an occasional cause of dental 
irregularities. It may occur in either jaw, but generally in the 
upper, and is due to hypertrophy on the one hand, or hyperplasia 
upon the other; also to osteitis, periostitis, continued irritation 
drawing blood to the part, and, in some cases, to disease of the 
antrum and nasal fossae, producing the same effect. Disease of the 
antrum may cause either periosteal or osteal enlargements. Hered- 
itary syphilis has an especial predilection for the bones, particularly 
at the junction of epiphysis and diaphysis. The growth of the teeth 
does not proportionately increase, and the consequent disproportion 
between the teeth and jaws necessarily produces a deformity. The 
forms of irregularities of the teeth that co-exist with crowded arches 
are not seen in enlarged jaws. Rachitis in children, whether due to 
syphilis or not, causes hypertrophy and hyperplasia of the jaws. 
The hypertrophy and hyperplasia may be localized in some portion 
of the jaw, causing it to be unevenly developed. 

The last, but not least, of the causes of arrested development of 
the maxillary bones which I shall mention is that due to consti- 
tutional diseases and the eruptive fevers. Debilitating acute diseases 
(fevers, the exanthemata, etc.) in children are sometimes followed 
by sudden overgrowth of bone, which is quite noticeable. This 
process affecting the jaw may account for certain proportions of 
those cases of measles and pneumonia which are followed by dental 
irregularities and maxillary deformities. In some cases, however, 
the process is a low grade of inflammation, which is followed by 
atrophy of the jaw instead of hypertrophy or hyperplasia. The 
special predilection of these processes for the superior maxilla is on 
account of its liberal blood and lymphatic supply, and the contiguity 



52 IRREGULARITIES OF THE TEETH. 

of such cavities as the antrum and nasal fossse, which, in many cases, 
contribute their quota of irritation. 

The question of diathesis enters largely into the etiology of maxil- 
lary and dental deformities. The physical characteristics of strumous 
children demonstrate this fact quite forcibly. The description of 
this diathesis given by Fothergill is decidedly apt in this connection : 
" This diathesis has an imperfectly developed osseous system as one 
of its characteristics. The bones are small, the shafts slender, the 
epiphyses enlarged ; the hands are often unshapely from this osseous 
defect ; the thorax is small ; the forehead is high and prominent ; the 
jaw is small, and the teeth crowded and carious." Persons of a 
nervous diathesis have small jaws, but not in disproportion to the 
rest of the osseous system. The jaws may be relatively small, how- 
ever, because the teeth frequently do not partake of the symmetrical 
smallness of the other bony structures. Constitutional diseases, such 
as the exanthemata, syphilis and phthisis, may affect the jaws in 
common with the other bony structures, and as the teeth do not vary 
much in size in different subjects, a relatively small jaw results in 
such cases. Dr. Florence Hunt, of the Cook County Insane Asylum? 
informs me that the majority of the Swedish and Norwegian patients 
are affected with scrofula and other constitutional diseases, and that 
post-mortems reveal soft and undeveloped epiphyses not unlike 
cartilages. 

The first effect of irritation of bone in any situation is a determi- 
nation of blood-supply with its attendant increase of nutritive mate- 
rial; soon proliferation of young connective tissue begins from the 
osteophytes and from leucocytes brought by the blood. The young 
connective tissue soon appropriates the necessary ossific material 
from the blood, and, after passing through the fixed connective- 
tissue period of its existence, becomes bone-cells and fibres. In some 
cases of malnutrition the period of ossification does not supervene, 
but the soft and spongy bone becomes atrophied, through the con- 
traction and hardening of the connective-tissue stroma formed in the 
pathological process of perverted bone-building. In some cases there 
occurs merely thickening of the pre-existing bone-structure, the new 
connective tissue being absorbed. This constitutes osteoplasia or 
true hyperplasia of bone. 

Where hypertrophy occurs, it may assume one of two forms, viz., 
an ivory-like hardness, or a spongy condition, indicating the exist- 



CONSTITUTIONAL CAUSES. 53 

ence of chronic osteitis. When these processes are localized we have 
one or the other varieties of osteoma or osteoid tumor. These vari- 
ous processes produce a variety of deformities dependent upon their 
extent and location. 

As has been previously stated, the irregularities of the teeth 
caused from a crowded condition do not exist in enlarged jaws. If 
the growth of the jaw is uniform throughout, spaces will exist be- 
tween the teeth as far back as the first permanent molars, diflTering 
in width in proportion to the relative positions of the teeth and 
articulations of the jaws. If the growth of the jaws is not uniform 
in the natural development, or is the result of disease, the anterior 
teeth will be influenced in the direction of the growth. In a majority 
of cases the molars of one jaw w411 antagonize uniformly with those 
of the other jaw. The first permanent molars form a fixed point 
of resistance in the posterior part of the mouth upon which the 
jaws rest, thus keeping the teeth in a fixed position, the second and 
third molars coming later and crowding against them. The only 
exceptions to this rule are cases where the molars have been ex- 
tracted too early, and where there are tumors of the jaws. As 
illustrative of the interesting character of some of these conditions 
described, I take the liberty to present a few cases which have come 
under my notice. 

Case L Arrest of development. Girl, age ten. Consumption on 
father's side ; cancer on mother's side. Child scrofulous, with small 
bones, especially the maxillary bones, which are unusually small. 
The teeth of both jaws (permanent first molars and incisors, tem- 
porary cuspids and molars) are in a very crowded condition. The 
teeth are normal in size. With such unusually small jaws, and the 
teeth at this age being very crowded, I shall watch this case with 
great interest. I shall expect to find marked V- or saddle-shaped 
arches. I have observed similar results in like cases. 

Case II. Arrest of development. Girl, age sixteen. When quite 
young had a severe attack of scarlet fever, and the arrest of the de- 
velopment of the bony framework resulted. The jaws are unusually 
small, and the teeth are crowded to such an extent that the cuspids 
remain outside the arch. 

Case III. Enlargement of the superior maxilla. George W., 
age fourteen. This boy was sent to me for an opinion in regard to 
his teeth. Upon examination I found the teeth of the normal size. 



54 IRREGULARITIES OF THE TEETH. 

Spaces existed between all the teeth as far back as the first perma- 
nent molars. The bicuspids were not fully developed, but were 
through the gum sufficiently to notice their position in connection 
"with the other teeth. The spaces were not uniform, those between 
the incisors being the largest. The widest space was between the 
central incisors ; the incisors of the lower jaw coming in contact with 
the mucous membrane of the mouth posterior to the superior incisors. 

Case IV. Hypertrophy of the jaw. J. B., age nineteen. This 
patient came under my treatment in June, 1887. "When fourteen 
years of age he received a blow upon the side the jaw. He is of a 
scrofulous nature. The blow produced a low form of inflammation, 
and hypertrophy of the bone supervened. The teeth of that side 
of the jaw were carried laterally, and spaces existed between the 
bicuspids and molars. 

Case V. Antrum disease. Boy, age seven. German descent ; 
born in this country ; scrofulous. Quite a deformity was noticed 
upon the left side of the face, produced by the bulging of the antral 
wall. Hypertrophy of the alveolar process also existed. The tem- 
porary teeth on the left side of the upper jaw extended beyond those 
of the lower jaw. Upon opening into the antrum a thick, ropy fluid 
exuded. After three months' treatment no improvement has been 
noticed. 

III. Development of the Inferior Maxilla by Exercise. 

The superior maxilla is influenced to a greater degree by the 
various causes of jaw-deformities than the inferior maxilla. The 
bones of the upper jaw are in direct contact with the other bones of 
the body, while the lower jaw, unlike all the other bones, develops 
independently, and is only attached at its remote extremities by 
articulation. The growth of the body of the bone is free to develop 
or to remain in a dwarfed condition, depending wholly upon its 
blood-supply for its nourishment. The superior maxilla, as has been 
stated in a previous paper, shows indications of gradually diminish- 
ing in size. The inferior maxilla, although under the same influ- 
ences, has a powerful factor to aid its preservation, viz., motion and 
exercise. On this account the question presents itself, as to what 
extent certain properties of the jaws, influenced by habit (use), may 
be transmitted. The tissues of the body especially those of the 
osseous and musclar systems, possess a certain degree of plasticity, by 



CONSTITUTIONAL CAUSES. 55 

which they are enabled to change their weight or shape. This 
quality depends upon the use of muscles and bones. Among verte- 
brates we find a close relation between the muscles and the bones 
upon which they are inserted. The union is made up of tendons, 
which are prolongations of the muscles to the periosteum, and the 
periosteum is attached to the bones. Powerful muscles and large 
bones are always associated, exercise developing them both simul- 
taneously. As outward changes occur in the life of human beings 
or animals, adjustment to environment tends to alter the physical 
charcteristics. These changes often occur through such gradual 
modifications that from one generation to another but little 
marked difference is noticed, but the structure, in the course of a 
number of generations, will so change that a new species will be 
developed. Any animal domesticated from a wild life shows this 
change, and among human beings the negro imported from Africa 
will, after several generations have a less prominent jaw-bone, and 
the frontal bone will become more prominent.* The changes, 
although existing in the white races, after intermarriage with other 
nations, are not so pronounced and rapid as in the negro cross-breed, 
but are gradually occurring. No part of the body demonstrates 
these changes so forcibly as the superior or inferior maxilla. 
The extremities must be measured and weighed to compare the two 
halves of the body. 

The accustomed eye can at a glance compare the jaws and teeth 
and observe the slightest deviation. AVhatever views are held re- 
garding the origin of man, it cannot be denied that the human jaws 
of the earlier races resembled those of the anthropoid ape, whose 
upper and lower maxillae protruded and were uniform. Observation 
will show that the changes in the shape of head and jaws are not 
confined to one race nor to past generations, but are continually 
progressing. These changes are not uniform in the two jaws. The 
superior maxilla is a fixed bone, and the inaction from lack of ex- 
ercise gradually affects and diminishes the volume of bone-tissue from 
one generation to another. 

The inferior jaw, on the other hand, is constantly in motion, which 
causes a flow of blood to the part, and the activity of nutrition in 
the muscles and bone increases their size and strength. This increase 

* In some instances, the laws of hereditary and sexual selection necessarily 
co-operate with environment in producing this change. 



56 IRREGULARITIES GF THE TEETH. 

of the bone by exercise of the part has been alluded to by C. Hart- 
ing in reports of examinations made. He says that " the bones of 
the right upper limb are generally larger than those of the left." 
This increase in size was not confined to one bone, but to all the bones 
of the right limb. The weight of the right arm without the hand 
is to the weight of the left arm without the hand as 106.2 : 100, a 
difference of about six per cent., which would indicate not only an 
increase in the volume of muscle, but in the weight of the bone. 
Exercise of the inferior maxilla, which has always existed, has de- 
veloped the jaw, while the superior maxilla has dwarfed from non- 
exercise. The contour and expression of the face depend, to a great 
extent, upon the shape of the inferior maxilla. Frequently this 
bone will exhibit peculiar family characteristics in early life. Of- 
tener, family resemblances are not established until the individual 
has attained his full growth, from the thirtieth to the fortieth year. 
Hereditary peculiarities may exist at birth, like the transmission of 
features, or color of eyes or hair but family likenesses may not ap- 
pear until middle life, like the contour of the face, shape of the 
nose, or shape or size of the inferior maxilla. Such being the case, 
it may be assumed that motion and exercise are the prime factors in 
assisting the development of the inferior maxilla. 

IV. Asymmetry of the Lateral Halves of the Maxillary Bones. 

Asymmetry of the lateral halves of the maxillary bones exists in 
the present era of the human race, and, like other irregularities and 
imperfections in the structure of the body, it prevails to a greater 
extent among the idiotic, the deaf and dumb, and among the off- 
spring of mixed races, than in clannish tribes or nations Each 
lateral half of the body develops independently of the other. The 
jaws, like other members, are influenced by the independent 
growth of the two halves, so that each has its own peculiarities. 
Asymmetry, therefore, is caused from an inharmonious lateral 
development of the parts. The superior and inferior maxillary 
bones, growing independently of each other, may be subjected to 
peculiar characteristics of environment, so that the result of their 
development may be asymmetry of the jaws. Extreme asymmetry 
of the lateral halves of the human body is frequently observed, and, 
as some of the recorded cases are of special interest, I will mention 
a few of them. 



CONSTITUTIONAL CAUSES. 



57 



These cases are so marked that they are noticeable by the most 
casual observer. In measuring the lateral halves of the body by 
the system of measurement of criminals and convicts introduced 
some years ago by M. Bertillon, we shall find that the halves do not 
harmonize in a single instance. These differences are not altogether 
inherited or natural, but have been acquired, to a certain extent, 
by exercise of the part. Marked illustrations of development by 
exercise are seen in the blacksmith, whose right arm is larger and 
will weigh heavier than the left. The peddler who carries a pack 
has the side most in use developed more than the other. 

If exact measuiements of the maxillary bones could be made, a 
lack of harmany in the lateral halves would be observed in weight, 
shape and size. The difference is generally not sufficient to affect 

Fig. 12. 




the contour of the face, but causes faulty articulation to the teeth 
upon that side of the face. The deformities of either lateral side of 
the superior maxilla are not necessarily like those of the inferior. 
Excessive growth or arrested development appear upon both sides 
of the jaws, sometimes on the right and again upon the left. Ex- 
aminations of these deformities can be made only when the second 
teeth have been extracted and the alveolar process has been absorbed. 
Fig. 12 shows the superior maxilla after absorption has taken 
place. If a line be drawn through the jaw at the median line, it 
will be seen that the left half is fully developed, while the right 
half is contracted at the bicuspid region. The following statistics 
show the deformities in the contour of jaws modeled by Dr. L. P 



58 IRREGULARITIES OF THE TEETH. 

Haskell, of Chicago, who has a large collection of models, and who 
kindly assisted me in their examination : 

Upper Jaw. 

Total No. examined 298 

Total No. normal 137 

Total No. abnormal, right side 73 

Total No. abnormal, left side 88 

Fig. 13 illustrates the inferior maxilla after the teeth have been 
extracted and absorption of the alveolar process has taken place. 
By drawing a line through the centre of the lower jaw at the 
median line, a wider space may be seen to exist between the line 
and the left side than on the other side. 

Lower Jaw. 

Total No. examined 154 

Total Ko. normal 54 

Total No. abnormal, right side -12 

Total No. abnormal, left side 88 

Fig. 13. 




In the study of irregularities of the teeth during the past eight or 
ten years, I have observed that, although no two cases of irregu- 
larities of the teeth are exactly alike, there is a general similarity of 
shape and outline of alveolar process and jaws, owing to similar 
environments during eruption of the teeth. Upon the hypothesis 
that the two halves of the superior maxilla are developed in pro- 



CONSTITUTIONAL CAUSES. 59 

portion to the excess of food masticated on one side or the other, 
depending upon right and left-handeduess of the individual, we sup- 
pose that the case illustrated is that of a left-handed person, as the 
left side of the jaw is larger. But it appears that this side is normal 
in size and the right is deficient in development. By examining 
carefully the contour of patients' teeth, we shall observe that but 
few arches are uniform. While one side may be normal the other 

Fig. 14, 




will be depressed. Fig. 14 shows such a deformity. This cut is 
taken from the model of an extreme case of irregularly-shaped jaw. 
It represents a perfect semi V-shaped arch. (I find in my collec- 
tion of models thirty-eight of this variety of deformity, twenty-four 
of which are on the right side and fourteen on the left.) Most of 
these irregularities are not quite as depressed at the cuspid region 
as the cut indicates. No two are exactly alike as regards the posi- 
tion of the teeth, and yet the similarity is so complete that a non. 
professional man would immediately take notice of it. The asym- 
metry of the jaw illustrated in Fig. 12 is probably caused by the 
peculiar arrangement of the permanent teeth in the arch, since the 
deformity is not apparent during the first set of teeth, the alveolar 
process and maxillary bones being molded into this peculiar shape 
thereby. Since but few people are left-handed, this percentage is 
very large, showing twenty-four out of thirty-eight cases with defi- 
ciencies on the right side, when we might look for normal or exces- 
sive development on that side. The cause of this irregularity I 
believe to be local in its origin, — viz., too early extraction of the 
temporary teeth upon the aflfected side : thus showing that one side 
is as liable to be aflfected as the other. The mechanism of this 
irregularity will be found under the head of local causes. 

The asymmetry upon the lower jaw may be traced to two causes: 
1st. The full number of teeth retained upon the long side. If the 
third molars should develop on one side only, the jaws on that side 



60 IRREGULARITIES OF THE TEETH. 

would expand by the crowded condition of the teeth and extend 
farther from the median line than otherwise. The loss of the third 
molars by extraction or non-development would prevent the other 
side from increasing to the natural size. 2d. The relation of the 
upper teeth to the lower teeth. The articulation of the inferior 
maxilla with the cranium is so remote, and the contour of the two 
bones so unlike, that uniformity of bone-structure cannot be looked 
for. When we consider the complexity of the development of bone- 
tissues, first of the maxillary bone, then of the alveolar process, and 
lastly of the two sets of teeth, it is a wonder that harmony ever 
prevails. 

Bibliography. 

(I) Harting, P. " Sur une Asymetrie du Squelette Humain se Transmettant 
Hereditairement." Arch. N^erl. d. Sc. Exactes, etc., La Have, 1869, iv. 
44-54. 

(2). Foucher. " Excessive Development of Left Arm and Leg." Bull. Soc. 
Anat de Paris, 1850, xxv. 108; 

(3) Hayden. " Congenital Atrophy, or Arrest of Development of the Right 
Upper Extremity." Dublin J. M. Sc , 1878, Ixv. 521. 

(4) Chassaignac. *' Hypertrophie Congenitale des Deux Menibres Droits, 
Taches Sanguines Multiples, Varices, etc." Bull. Soc. de Chir. de Paris, 
1857-58, viii. 452. 

(5) Hulke, J. W. " A Case of Complete Absence of both the Upper Limbs 
and Faulty Development of Eight Lower Limb." Med. Chir. Jr., London, 
1877, Ix. 65-69. 

(6) Smith, G. H. "Malformation of both Extremities on the Right Side.', 
Lancet, Lond., 1841-42, i. 358. 

(7) Guerin, J. J. " An Abnormality." (Left side undeveloped.) Canada 
Med. & S. J., Montreal, 1881-82, x. 655. 

(8) Birkett, J. " Case in which the Right Leg has Grown Longer than the 
Left, and the Right Patella has become Hypertrophied." Trans. Path. Soc. 
Lond., 1867, xviii. 284-287. 

(9) Lonsdale, E. F. " Case of Curious Deformity of the Lower Extremity 
from Arrest of Development ; Deformity of the Upper Extremity also." Ibid., 
1851-52, iii. 464-468. 

(10) Caizergues, R. "Arr^t de Developpement du Cote Gauche," etc. 
Montpellier Medical, 1879, xliii. 248-251. 

(II) Broca, P. " Inegalite Congenitale des Deux Moities du Corps; Sin- 
gulieres Consequences physiologique." J. de la Phys. de I'Homme, Paris, 
1859, ii. 70-74. 

(12) Burlet, P. ''Observation sur une Inegalite Congenitale des Deux 
Moities du Corps ; Hypertrophie Congenitale de Tout le Cote Droit." Mem. 
Soc. d. Sc. Med. de Lyon, 1862, i. 225-230. 



CONSTITUTIONAL CAUSES. 61 

(13) Charcot et Turner. " Exemple d'Atrophie Cer^brale, avec Atrophic et 
Deformations dans une Moitie du Corps." Comptes Eendu, Soc. de Biologie 
(1852), Paris, 1853, iv. p. 191. 

(14) Devogues. "Predominance du Developpement du Cote Droit sur le 
Cote Gauche," etc. Bull. Soc. Anat. de Paris, 1856, xxxi. 510-518. 

(15) Howden, J. C. "A Case of Atrophy of Eight Hemisphere of Cere- 
brum and Left Side of Cerebellum, with Atrophy of the Left Side of the 
Body." J. Anat. & Phys., Lond., 1875, ix. 288-296. 

(16) Hubbard, J. C. ''A Case of Asymmetry of the Two Halves of the 
Body." Ibid., 1871, N. S., Ixi. 289. 

(17) Lorinser, F. " Uber den Einfluss der Ungleichseitigen Korperentwick- 
elung auf die Wirbekaule." Alig. Wien. med. Ztg., 1872, xvii. 637. 

(18) Perroud. " Observation d'une Inegalite des Deux Moities du Corps ,' 
Crises Epileptiformes avec Diminution de I'lntelligence," etc. (Mem. Soc. de 
Med. de Lyon, 1862, i. 332-334.) 

(19) Du Plessis. " Nouveau Cas d'Asyraetrie Unilateral Cong^nitale de 
Toute la Moitie Gauche du Corps, chez une Jeune Fille de 16 Ans." Bull. 
Soc. de la Suisse Kom., Lausanne, 1871, v. 24, 31. 

(20) lay lor, T. " A Case of Unilateral Atrophy," etc. Tr. Clin. Soc, Lond., 
1878, xi. 118-123. 

V. — Asymmetry of the Maxillary Bones. 

HaskeWs Deformity.'^ — When we examine models of the superior 
maxilla after absorption of the alveolar process has taken place, we 
observe that in the cuspid and bicuspid region, high above the 
alveolar border, a marked depression exists on either side. Fig. 15 
shows a base-plate which has been formed over such a model. The 
plate is more depressed at the left than at the right side. This 
peculiar deformity is familiar to the operator who arranges teeth 
and waxes up plates for the purpose of restoring the contour of the 
face. Upon closer inspection of the model it w^ill be seen that there 
is an asymmetry of the lateral halves of the maxillary bones. With 
Dr. Haskell's assistance I have examined 298 models, finding 268 
out of the number with marked depression on the left side, and 24 
with the depression on the right side, and only six cases showed 
both sides to be alike. It is remarkable that so large a proportion 
of the cases of this deformity should be found existing on the left 
side. 

* I have named this deformity " Haskell's Deformity," for the reason that 
Dr. Haskell called the attention of the profession to this peculiar condition of 
the maxillary bone years ago, personally and through the journals, and saya 
he has found but one dentist who had observed it. 



62 IRREGULARITIES OF THE TEETH. 

Dr. Haskell says, " For many years I have observed a marked 
difference between the right and left sides of models of both the 
upper and lower jaws, but more especially noticeable in the upper 
jaw. It is not so apparent upon a casual glance at the model, for 
it is not so much in the alveolar process as in the maxillary bones. 
But a plate swaged upon a model from an impression taken high 
over the region of the cuspids (as ought always to be done) shows 
at once the depression of the left side, which occurs, to a greater or 
less extent, in 95 per cent, of cases. The difference becomes appar- 
ent in arranging artificial teeth. Every dentist of experience must 
have observed that greater length of teeth and gums is required 
upon the left side than upon the right How often it is seei? that 
the left side of the lip rises higher, in talking and laughing, than 
the right side. The difference in the two sides of the lower jaw does 




not occur as often, but is apparent in the divergence of the left side 
from a line drawn through the centre of the model, so that the pos- 
terior teeth on that side must be set farther in upon the plate." 

Dr. Haskell has, during the past twelve years, frequently called 
my attention to this peculiar deformity of the jaw. My own obser- 
vation of models and patients has also indicated the probability 
that the majority of deformities of this nature exist on the left side. 
The following theory for this deformity suggests itself as worthy of 
our consideration: Man, like some other members of the animal 
kingdom, moves the lower jaw from right to left in mastication. 
The constant friction of the lower teeth against the upper carries 



CONSTITUTIONAI. CAUSES. 63 

the superior arch with the alveolar process towards the left. By 
pressing the index finger over the cuspid and bicuspid roots, above 
the alveolar process, we shall find that the majority of mouths con- 
tain teeth with their roots standing out more prominently upon the 
right side than upon the left side. The right superior dental arch, 
like the arch of a bridge, resists such inward force because of the 
lateral contact of its teeth. On the contrary, the left superior den- 
tal arch may thus be carried slightly outward. The limited lateral 
motion during occlusion prevents the teeth and alveolar process from 
being carried farther. The cuspid tooth may be prevented from 
being carried in as far as it otherwise would be owing to the lateral 
motion of the lower jaw to the left. The alveolar process is thus 
carried beyond the border of the maxillary bones. After the teeth 
have been removed, absorption of the alveolar process occurs, leav- 
ing only the alveolar ridge. The ridge then overhangs the maxil- 
lary bone, thus producing a depression upon the left side. This is 
the reason that, in arranging artificial dentures in many cases, the 
teeth are carried over the alveolar border farther than upon the 
right side to obtain proper articulation with the natural teeth upon 
the lower jaw. 

On examining the model upon which the base-plate was formed, 
it will be seen that both the right and left alveolar borders are sym- 
metrical. The alveolar border in most cases indicates the contour 
of the teeth when in position. 

VI. Asymmetry in the Eami. 

A case recently seen with Dr. G. Frank Lydston, of this city, is a 
marked illustration of congenital maxillary asymmetry. The man 
is thirty years of age. The inferior maxillary is small and the chin 
pointed and narrow. There is a difierence of one-half an inch in 
the length of the r^mi, the left rami being the shortest. The differ- 
ence is sufiScient, when the face is smoothly shaven, to produce a 
noticeable deformity. The teeth are irregular in both jaws, the ir- 
regularity, however, being most marked in the superior jaw. The 
cranium partakes of the asymmetry, and the frontal suture is plainly 
marked. Numerous irregularities of the surface of the skull are 
observable. The larynx is displaced at least one- half an inch from 
the median line toward the left side. There is no history of injury, 
and a point of interest in this case is the fact that the asymmetrical 



64 IRREGULARITIES OF THE TEETH. 

and small jaw is a family characteristic, and has been noticed for 
several generations. The jaw, in this case, resembles the father's, 
while the arrangement of the teeth is similar to that of the 
mother. The upper portion of the body appears to have been 
developed in two lateral halves, and when brought together the left 
side of the body was higher than the right side. The cranium and 
maxillary bones show this deformity quite conspicuously. The teeth, 
which are comparatively sound, are all present. The left superior 
maxilla is considerably higher than the right. Occlusion is perfect, 
thus compensating for the short left ramus. 

VII. Asymmetry in the Body and Improper Occlusion. 

The daughter of an old patient of mine came to me for treatment 
September 14, 1888. She was about seventeen years old, and had 
quite a prominence upon the right side of the lower jaw, and another, 
although not so marked, upon the left upper jaw. The left corner 
of the mouth was nearly one-quarter of an inch higher than the right. 
The face was full and had a peculiar expression, owing to the mouth 
and jaw being at an angle when closed. Upon exammation, I found 
the left superior maxilla one-quarter of an inch higher than the 
right side. The alveolar process and teeth shared the same irregu- 
larity, thus placing the line of the teeth on the same plane as the 
lips. The body of the inferior maxilla, from the symphysis to the 
angle, seemed to be longer upon the left side than upon the right. 
When the jaw closed, the median line of the lower jaw was half an 
inch to the right of the upper. The lingual cusps of the biscuspids 
and molars on the right side of the lower jaw occluded with the 
buccal cusps of the bicuspids and molars of the upper, and vice versa 
upon the left side. 

The two cases just described are interesting from the fact that 
while the causes and the external appearances of the face are entire- 
ly different, the alveolar processes and the occluding surfaces of the 
teeth are on the same angle, the inclination being in the same direc- 
tion. This deformity is frequently found in the mouths of patients 
over forty years of age, where all the teeth have been removed upon 
the side of one jaw and upon the opposite side of the other, the 
alveolar processes containing the teeth elongating upon the side 
where there is no antagonism, and throwing the occluding line of 
the teeth out of position at an angle similar to that above described. 



CONSTITUTIONAI. CAUSES. 65 

By examining the mouths of 1977 idiots there were found to be 
159 with protrusion of the superior maxilla, and 92 with protrusion 
of the inferior maxilla. These deformities do not exist to such an 
extent among healthy individuals. This inharmonious development 
of the maxillary bones may extend from the articulation to the 
incisor teeth. Such deformities are rarely found in connection with 
the first set of teeth. When the superior maxilla protrudes during 
the period of the temporary teeth, it is usually caused by thumb- 
sucking. Protrusion of the inferior maxilla is the result of the 
abnormal development of the rami or body of the jaw. As these 
abnormal conditions usually correct themselves when the temporary 
teeth are shed, they consequently receive little attention. But 
where these deformities arise during second dentition the jaws are 
determined towards false positions, thus endangering the beauty of 
the face. We occasionally see excessive growth or hypertrophy of 
the superior maxilla. When the teeth are normal in size they appear 
small in proportion to the abnormally large jaw. They are carried 
forward with the alveolar process to such a degree that the teeth 
and lips may protrude. In such cases it appears as if the body or 
rami of the inferior maxilla were much shorter than is natural, but 
by close inspection we shall see that the inferior maxilla is normal 
and quite a space exists between the superior and inferior central 
incisors. Protrusion of the superior maxilla is a common defect ; it 
is accompanied by a depression of the face at the root and alee of the 
nose, and a protrusion of the anterior alveolar process and upper lip. 
If the maxillary bones, as well as the alveolar process, are enlarged, 
the teeth will stand perpendicularly with the alveolar process. If 
the superior maxillary bones are small, the teeth will protrude from 
the perpendicular to an angle of 45°, Such a case is illustrated by 
Fig. 64, page 131, Kingsley's "Oral Deformities," and in Fig. 180, 
page 145, Talbot's "Irregularities of the Teeth ; " this is a deformity 
frequently met with in practice. A common cause of protrusion of the 
superior maxilla is illustrated in Fig. 16.* The teeth in the upper 
jaw are fully erupted, but are directed downward and forward. 
The teeth in the lower jaw are in their proper position. It will be 
observed that the rami of the jaw are inharmoniously developed, the 
rami being so short when the jaws close, that the occlusion throws 
the superior teeth and alveolar process forward. In this case the 

* These cuts represent cases in my practice. 



66 



IRREGULARITIES OF THE TEETH. 



alveolar process is quite thin, because the arch is high and the teeth 
having long slender roots are easily carried forward. The inferior 
maxilla is large, the structure dense and hard, and the teeth firmly 
fixed in position in the jaw. When occlusion takes place, the weaker 
structure (the superior maxilla) is carried forward by the stronger 
(the lower maxilla), thus forcing the alveolar process forward. The 
shortness of the rami of the inferior maxilla causing improper 
closing of the jaws is a feature strongly impressed upon the dentist 
who undertakes to insert artificial dentures. The tendency of 
the lower jaw to force an upper denture out of the mouth, by 
striking the teeth at an angle instead of perpendicularly, is a marked 

Pig. 16. 




illustration of the inharmonious development of the jaws. The 
same difficulty is frequently experienced with the partial lower plate 
when it presses against the anterior teeth and alveolus, forcing 
them both forward by improper articulation. The occasional grind- 
ing of the surfaces of the artificial molars to produce proper articu- 
lation affords another illustration of the effects of this inharmonious 
development. 

VIIT. Imperfect Occlusion. 

Fig. 17 illustrates a deformity produced by the before-mentioned 
cause ; yet the result is very different. The case is that of a boy 
fourteen years old. Before the eruption of the second molars, the 
articulation was perfect ; but as soon as the second molars occluded, 



CONSTITUTIONAL CAUSES. 



67 



the jaws were forced open. The rami are so short that when the 
second molars and the alveolar processes of the superior and inferior 
maxilla come together, a space exists between the central incisors. 
Unlike the former case, the superior alveolar process is re- 
markably well developed, and the teeth are firmly fixed in the 
jaw. The vault of the mouth is quite low. The position of the 
teeth in the alveolar process is such that when the lower teeth oc- 
clude, they strike directly on a line with the long axes of the roots, 
thus preventing the forward movement of the teeth and alveolar 

Fig. 17. 




process. The inferior maxilla is not well developed, nor has it the 
power to overcome the resistance, and force the superior alveolar 
process and teeth forward, as exemplified in Fig. 16. When the 
rami are short, so that they do not harmonize with the maxillary 
bones, the movement of the jaws may be likened to the arras of 
shears : the farther the points are from the centre, the greater dis- 
tance they have to travel. A slight movement at the centre will 
cause them to move a considerable distance. In a similar manner, 
a slight excessive protrusion of a molar will cause the anterior 
teeth to become separated. The shorter the rami, the less the har- 
mony between the jaws and teeth. The farther back the protru- 
ding molar, and the more it projects, the greater the anterior sepa- 
ration of the jaws. The excegsive eruption of the second and third 
molars is often due to the persons sleeping with the mouth open. 
Not infrequently the mal-occlusion of the teeth is due to the 
inability to close the jaws on account of the inharmonious develop- 



68 



IRREGULARITIES OF THE TEETH. 



ment. OccasioDally there are mouths in which the molars and 
bicuspids occlude, and there is just enough space between the cen- 
trals to admit a thin spatula. January, 1887, a patient was brought 
to me for advice whose jaws, when closed, showed a space of half 
an inch between the incisors. The pressure of the jaws upon the 
molar teeth is, in some instances, so great that normal eruption is 
impossible. In such cases the molars will protrude through the 
gum, and the superior and inferior processes will occlude when the 
jaws meet. 

IX. Protrusion of the Inferior Maxilla. 

Protrusion of the inferior maxilla produces one of the most repul- 
sive deformities of the face, and should be corrected as early in life 
as possible. When it is caused by or associated with arrested de- 

F1G.-18. 




velopraent of the superior maxilla, it is extremely difficult to restore 
the features to a natural expression. A case of considerable inter- 
est, illustrated by Fig. 18, came to my notice in 1887. A commer- 
cial traveler from New York called at my office for the purpose of 
having a gold crown re-set. I noticed a marked deformity in the 
jaws, consisting of a depression at the alse of the nose and an unu- 
sual protrusion of the inferior maxilla. Upon examination I found 
that the second molar on the upper jaw and the third molar on the 
lower jaw were the only teeth that occluded. This was caused by 



CONSTITUTIONAL CAUSES. 69 

an excessive length of the rami of the lower jaw. The body was 
normally developed, but was carried forward by a lengthening of 
the rami. There are cases where the lower jaw projects beyond the 
upper; but by closely examining the deformity, we find that an- 
other cause exists for this appearance. 

A girl fifteen years of age was sent to me for treatment by a 
dentist from a neighboring State. He desired me to " force the 
inferior maxilla back into place." I found the rami and body of 
the jaw apparently normal. The external appearance of the chin 
and cheeks was in keeping with the outline of the face. I observed 
that the upper lip was much depressed, and that deep lines extended 
from the alee of the nose to the corner of the mouth. Upon opening 
the mouth, I found arrest of development of the superior maxilla. 
The superior incisors closed inside of the inferior incisors ; the first 
and second bicuspids, first and second molars, were in position, but 
had crowded forward close to the lateral incisors. The cuspids were 

Fig. 19. 




quite outside of the arch. The superior dental arch had to be 
forced out, instead of carrying the inferior maxilla in, which would 
tend to further complicate the case. In the majority of cases which 
appear to result from a protrusion of the lower jaw, we shall find 
that the lower maxilla does not project abnormally ; but the supe- 
rior maxilla being arrested in its development gives the protruding 
appearance to the lower jaw. Before undertaking to correct such 
a deformity, the general contour of the face should be carefully 
studied. 



70 



IRREGUI.ARITIES OF THE TEETH. 



A peculiar but rare deformity of the inferior maxilla is illustrated 
in Fig. 19. The body of the jaw is very short. A line dropped per- 
pendicularly and touching the chin at the median line would pass 
through the bicuspid region of the superior maxilla. A front view 
of such a deformity gives an appearance as though the lower jaw 
were absent, and a side view throws the nose out prominently, while 
the chin and forehead retreat. The rami of the jaw are larger than 
the body. The articulation is good, the defect being that in the 
incisor region the teeth strike quite a distance posterior to the 
superior incisors. Arrest of development of the lower jaw frequently 
results when the superior incisors are crowded inwards irregularly. 
The lower incisors coming in contact with them, thus preventing 
the forward development of the body of the jaw. 




Fig. 20 represents jaws such as are frequently seen. The long 
body and protruding chin, narrow and contracted alveolar process 
on the lower jaw, a small superior maxilla and thin protruding al- 
veolar process are in keeping with the thin faces and sharp features 
of the class. The body of the inferior maxilla is small, thin and 
very delicate ; the rami unusually short — ^just the opposite to the 
one last described. A line drawn parallel with the occluding sur- 
faces of the teeth would meet the angle of the jaw, which, in a nor- 



CONSTITUTIONAL CAUSES. 



71 



maljaw, would extend from one to one and a half inches below the 
line. Naturally slender, delicate muscles and tendons are associ- 
ated with such bones. In these cases dislocation of the inferior 
maxilla is liable to occur while yawning or during dental opera- 
tions, so great is the leverage. In this instance the length of the 
jaw compensated for the width, so that in this particular case the 
teeth are not irregular, although irregularity frequently accom- 
panies this peculiar formation of the jaw. This is particularly the 
case with the saddle or V-shaped arches on the upper jaw and the 
saddle-shaped and forward inclination of the molars, bicuspids and 
cuspid teeth on the lower jaw. The roof of the mouth is also very 
high and the alveolar process very thin, giving the roots of the 
teeth but slight support. The same principle of organization and 
structure is operative in the alveolar process and teeth of the lower 
jaw. 



Fig. 21. 



Fig. 22. 




Fig. 21 represents the jaws of a patient twenty-six years of age 
who came to me for treatment. Upon examination I found a small 
normal inferior maxilla, well protruded and in harmony with the 
other features of the face. The superior maxilla and alveolar pro- 
cess were excessively developed, the first molar and anterior teeth 
describing a much larger circle than the lower. The second 
molars were the only teeth that articulated properly. The anterior 
alveolar process had taken on a prolific deposition of bone cells 
until the teeth impinged upon the gum of the lower jaw, producing 
absorption and expansion. The upper lip was covered with a mus- 
tache which completely hid the deformity. Under such conditions 



72 IRREGULARITIES OF THE TEETH. 

a prominence is observed at the alse of the nose, the upper lip being 
drawn over the alveolar process. 

Fig. 22 represents a case often met with. The body of the in- 
ferior maxilla is excessively developed, the extent of the irregularity 
depending on the degree of development. When only a slight pro- 
trusion exists the incisors strike beyond the superior incisors. 
In extreme cases only the molars articulate. When only the an- 
terior teeth articulate the alveolar process develops so that the teeth 
extend to the superior alveolar process. The features may be quite 
regular otherwise. This deformity is common among Negroes, 
and is called prognathism. 



CHAPTER IV. 

CONSTITUTIONAL CAUSES— Continued. 

B. ANOMALIES OF JAWS THAT AKE THE KESULT OF 
FUNCTIONAL DEKANGEMENT. 

Irregularities resulting from functional derangement are con- 
fined to the individual, i. e., not seen in the parents, though func- 
tional derangement of the parents usually give rise to them. Parents 
of such individuals may have suffered from a lack of proper nervous 
function due to some form of starvation, as the insane, rachitic, 
scrofulous, or there may have been an excess of nervous function, due 
to over-stimulation. Thus the second class can be subdivided under 
two heads : 

(1) Irregularities resulting from malnutrition. 

(2) Irregularities resulting from over-stimulation. 

It is apparent that these two classes merge into each other, in- 
asmuch as they both terminate in unbalanced function. Both are 
the result of violating the laws of nature — the former by inhar- 
monious development and function of organs, the latter by an excess 
of use. 

The first division is most frequently found among idiots, insane, 
the blind, and is generally characterized by extreme stupidity and 
ill-favored exterior and disease of the nerve-centres. The second di- 
vision has decided neurotic tendencies, other functions being more 
or less impaired by these. There is often a marked degree of in- 
tellectual activity, and more or less personal beauty. Cases of this 
kind are usually found in good families where one or both parents 
have taxed the brain or the nervous system to excess. 

We thus find that the children of the under-fed and the children 
of the over-stimulated may present abnormal jaws, though otherwise 
they may be very difl^erent physically, certain forms of irregularities 
being found both in the idiotic and the highly intellectual. 

73 



74 IRREGUI.ARITIES OF THE TEETH. 

IKREGULAEITIES RESULTING FROM MALNUTRITION. 

I. Prevalence of Maxillary Deformities in Idiots. 

Dr. W. W. Ireland has defined idiocy as "mental deficiency 
or extreme stupidity depending upon malnutrition or disease of the 
nerve-centres, occurring before birth or before the evolution of the 
mental faculties in childhood." A definition that seems moreinclu. 
sive, and that more clearly describes the tissues of the body, is the 
one given by Dr. Shuttleworth : " A vice of the entire organism ; 
an affection not only of the nervous system but of the functions 
generally of organic life." Not a tissue of the body is exempt ; the 
phenomena that check development of the brain-tissues will also 
interfere with proper development of the other tissues of the body. 

No part of the body has received the impress of disease so 
markedly as the osseous system, and yet pathologists have given 
this part of the idiotic system but little attention. This osseous 
system seems to have been constructed regardless of symmetry or 
uniformity. While in the normal individual the lateral halves are 
never uniform, in the feeble-minded the greatest asymmetry prevails. 
This want of harmony is more apparent in the maxillary bones 
because of their peculiar formation and environment. The close 
proximity of the jaws and their articulation permit of irregularities 
being readily observed At the beginning of my examinations I 
observed that other deformities than the V- and saddle-shaped ex- 
isted, all of which must be considered. I found both excessive and 
arrested development of the maxillary bones ; arrest of the one and 
excessive development of the other ; protrusion of the upper or 
lower jaw ; high or low vault ; partial V- and partial saddle-shaped 
arches; semi- V and semi-saddle-shaped arches; semi-V and semi- 
saddle-shaped on the same side, and small teeth. 

Of late years some American investigators have made examina- 
tions among the inmates of our institutions for idiots, and reported 
that they found about the same proportion of irregularities as may 
be seen in ordinary practice. 

I believe myself warranted in the assertion that a much larger 
percentage of deformities of the teeth and jaws exists among a given 
number of imbeciles, deaf and dumb, and blind than in the same 
number of normal individuals, the various conditions being the re- 
sult either of arrested development or excessive growth. 

It is obvious that any condition of malnutrition, particularly if 
existing during the period of embryonal and infantile growth and 



CONSTITUTIONAI. CAUSES. 



75 



development, which is sufficiently marked to cause perversion of 
growth in the complex nervous centres, must necessarily affect the 
tissues in general. Nerve-tissues have relatively greater vitality 
than the other tissues of the body, and every physician knows that 
the brain and spinal cord will often functionate after the other 
structures of the body have been seriously impaired by disease. 

The varying opinions among scientific men on either side of the 
Atlantic led me to investigate the subject carefully. The exami- 
nations were made by myself and by able dentists in the following 
named institutions : 

Asylum for Idiots of the State of New York, at Syracuse ; Massa- 
chusetts School for Feeble-minded, at South Boston ; Illinois Asy- 
lum for Feeble-minded Children, at Lincoln ; Asylum for Idiots, 
Eandall's Island, N. Y. ; Minnesota Training-school for Idiots and 
Imbeciles, Faribault ; Kansas State Asylum for Idiots and Imbe- 
ciles, South Winfield; Cook County Insane Asylum, Dunning, 
111. ; Pennsylvania Institution for Feeble-minded Children, at 
Elwyn. 

(Special reports may be found in the Transactions of the Inter- 
national Medical Congress, 1877, and in the Annual, 1888.) 

The following tables show the total number of irregularities in 
each grade and sex : 

Total Deformities in the Jaws * 



o 
S5 




1 

izi 




hi 

92 


1. 

Opl-5 


l| 






4= ^ 

II 


Hi 

'S ja i 


=35 


1977 




1095 


152 


159 


318 


129 


236 


31 


207 


71 


Per cent. 


55.3 


7.6 


4.6 


7.9 


16. 


6.5 


ll.P 


1.5 


10.4 


3.5 



The above tables show that almost one-half of the whole number 
examined had irregularities of the jaws and teeth. The examined 
children were over nine years of age. Under that age irregu- 
larities might be considered as of local origiUj while constitutional 
and developmental irregularities do not appear until the eruption of 
the incisors and first permanent molars. As would be expected, the 

* All tables show irregularities that are the result of small jaws. 



76 IRREGULARITIES OF THE TEETH. 

largest percentage of irregularities is found in the low-grade class ; 
and it is seen that the normal classes in the high and middle grades 
vary only about 12 per cent. ; the middle grade showing the largest 
percentage of normal jaws and teeth, the high grade the next, and 
the low grade the fewest number of normal cases. 

The mental capacity of the idiot can indicate in a general way 
only the abnormal condition of the osseous as well as muscular, 
venous and arterial systems of the individual ; thus, a high-grade 
idiot might possess an atrophied condition of any of the tissues of 
the body, while a low-grade idiot might de\relop any or all of the 
tissue to an excessive degree, thus depending, of course, upon the 
inclination and condition of the blood-supply. Thus the arterial and 
nervous systems might be atrophied on one side, lessening the sup- 
ply of blood to that side or limb, and producing atrophy of the 
muscular and osseous tissues on that side. The opposite effect 
might be produced on the other side ; a large amount of blood 
would be carried naturally to the extremities of the other side, 
causing hypertrophy of tissue. 

If these tissues of the body are so prone to take on abnormal 
conditions, certainly the jaws must suffer more or less. I have 
observed three conditions that account for nearly all the irregulari- 
ties of the jaws and teeth : excessive development, arrest of develop- 
ment, and inharmonious development of the maxillary bones. 
These abnormalities are developed with the osseous system, and 
may be properly termed constitutional or developmental. 

When excessive development occurs in one jaw, and the other is 
normal, or arrested development ensues, then the teeth in the ab- 
normally large jaw protrude. 

If the cranium is large, the superior maxilla is usually larger 
than normal. When the inferior maxilla is involved, the rami are 
as likely to be enlarged as the body of the bone. Sometimes the 
rami and the body develop uniformly. When there is excessive 
development of a part or all of the bone, protrusion of the lower 
jaw and teeth takes place. I have seen cases in which one half of 
the superior and inferior maxillae, as well as one-half of the cra- 
nium, was larger than the other. In these irregularities of the 
jaws, however, irregularities of each set of teeth are seldom seen. 
While it is proper to speak of these conditions as irregularities, yet 
they are so only as one jaw is related to the other. 



CONSTITUTIONAL. CAUSKS. 77 

I have already shown, in a paper read before the Dental Section 
of the American Medical Association in 1888, that irregularities of 
the teeth, which I have termed constitutional, prevail to a greater 
extent among the idiotic, deaf and dumb, and blind than among an 
equal number of strong and well- developed persons ; that not only 
is the brain-matter deficient in the feeble-minded, but that many 
cases are seen which show that the osseous system is generally de- 
fective ; and that when the bone-tissue is arrested in development 
from malnutrition, the maxillary bones are affected. 

It is frequently the case that when idiocy appears in a family, 
other members of the family are observed to be scrofulous, deaf, 
dumb, blind, or insane, showing that the conditions indicating 
neurotic tendencies have been transmitted through generations. 

In his work on '* Insanity in Norway," Ludwig Dahl gives many 
instances in which the result of this tendency is deafness, dumbness, 
or insanity, as often as idiocy. He says, " Acquired insanity and 
idiocy frequently appear side by side in the same family stock. 
Deaf-dumbness occurs frequently." He has traced the genealogies 
of a number of families, and has brought to light a number of 
interesting facts. In his genealogy of No. 3, the Ejvinds family 
have nine insane or idiotic, four deaf and dumb, and one epileptic. 
Other families showed a similar proportion of mentally and physi- 
cally deformed persons.* 

In his work on *' Idiocy and Imbecility," p. 528, Dr. Ireland 
says, " Deafness frequently occurs in families where some of the 
other members are idiots.'' And again, on page 16, " The children 
of epileptics are frequently insane or idiotic or hysterical, and the 
descendants of an insane person are often epileptic, idiotic, or in- 
sane. Deaf-dumbness, chorea, locomotor ataxia, hysteria, and other 
disorders of the nervous system now and then occur in the descend- 
ants, apparently as the result of an inherent neurotic tendency in 
the family.*' 

In the report of the Commissioner on Idiocy appointed by the 
Legislature of Connecticut (see Report of Commissioners on Idiocy 
to the General Assembly of Connecticut, New Haven, 1856, p. 35), 
it was found that out of seventy cases of idiocy there were ten cases 

* Lombroso has called attention to deformities of the jaws among the born 
criminals. 



78 IRREGULARITIES OF THE TEETH. 

of idiotic parents, six insane persons, six insane relatives, eight epi- 
leptic parents or relatives, eight blind and two melancholic. 

Dr. Howe shows (" On the Causes of Idiocy," Edinburgh, 1858, 
p. 35) that in seventeen families in Massachusetts the heads of 
which were blood-relations, there were born ninety-five children, of 
which forty-four were idiotic, twelve scrofulous and puny, one deaf, 
and one a dwarf. Morel and the school of investigation which he 
founded point out that the defective classes — i. e , the congenital 
deaf mute, blind, lunatic, idiotic, criminals, and paupers — are buds 
on the same tree of human degeneracy. In dealing wdth the evi- 
dences of degeneracy they cite defective teeth as one of the signs in 
most instances. These signs are atavism or reversion to lower types 
of structure and function. Many more cases could be given show- 
ing that a relation exists between the deaf, dumb, blind, and in- 
sane, but it is evident that the offspring of parents showing neurotic 
tendencies and symptoms are subject to these conditions. Medical 
men have commonly classified these lesions under the same head, 
and some specialists go so far as to classify the criminal and drunk- 
ard in this category. I have recently read an article from a 
French journal in which a left-handed person was also included. 

While specialists have generally concluded that most of these 
conditions are derived from a common neurotic ancestry, the only 
common feature is a very low grade of cerebral development. In 
my investigations concerning the osseous system in its relations to 
the irregularities of the jaws and teeth, I have observed a lesion 
common to all these conditions. With this object in view I have 
made examination of the mouths of all these classes except the 
criminal, and these I hope to examine in the near future. I found 
great difficulty in enlisting sufficient interest on the part of superin- 
tendents of Blind Asylums to enable me to make proper examina- 
tions of the blind, their reason being that the sensitive nature of 
the patients would not permit of their exhibiting the mouth for 
examination. I have conducted a sufficient number of examina- 
tions, however, to make some estimate of the percentage of deformi- 
ties of the jaws and teeth. 

II. Prevalence of Maxillary Deformities among the 
Deaf and Dumb. 

The greatest interest has been shown by the superintendents of 
Deaf and Dumb Institutions, thus enabling me to make very satis- 



i 



CONSTITUTIONAI^ CAUSES. 



79 



factory examinations. In some of the institutions visited, the blind 
are retained with the deaf and dumb; when such was the case the 
blind were classed with the deaf and dumb. The examinations were 
made either by myself or by able dentists living in the town or city 
where the institution was located. Examinations were made in the 
following institutions : 

Minnesota School for the Deaf, Faribault, Minn. 
Portland School for the Deaf Portland, Me. 
Oregon School for Deaf Mutes, Salem, Oregon. 
Milwaukee Day School for the Deaf, Milwaukee, Wis. 
Arkansas Deaf Mute Institute, Little Rock, Ark. 
Washington School for Defective Youth, Vancouver, Wa^h. 
Iowa Institute for Deaf and Dumb, Council Bluffs, Iowa. 
Clarke Institute for Deaf Mutes, Northampton, Mass. 
Evansville Deaf-Mute School, Evansville, Ind, 
Institution for the Deaf, Dumb and Blind, Berkeley, Cal. 
Kansas Institute for the Deaf and Dumb, Olathe, Kan. 
Institute for the Deaf and Dumb, Austin, Texas. 
Nebraska Institute for the Deaf and Dumb, Omaha, Nebr. 
Alabama Institute for the Deaf and Blind, Talladega, Ala. 
Indiana Institute for the Deaf and Dumb, Indianapolis, Ind. 
New Jersey School for Deaf Mutes, Trenton, N. J. 

South Carolina Institution for the Education of the Deaf, Dumb and Blind, Cedar 
Springs, S. C. 

Western Penna. Institute for the Deaf and Dumb, Pittsburgh, Pa. 
Colorado Institute for the Deaf and Dumb, Colorado Springs, Colo. 
Northern New York Institute for Deaf Mutes, Malone, N. Y. 

The following tables show the result : 

Total Deformities in the Jaws of the Deaf and Dumb. 



6 


m 


B 
1 




In 


III 




> 


1^ 
> 


■a a <- 


11 


nil 

824 


Male. 
Female. 


588 
363 


197 
108 


41 
51 


116 

89 


241 
177 


91 

78 


115 

77 


108 
95 


51 
62 


1935 


... 


901 


305 


92 
4.7 


205 


418 


169 


192 


203 


113 


Per cent. 


45.3 


15.7 


10.5 


21.7 


8.7 


9.9 


10.4 


5.8 



Two cases cleft palate. 



80 



IRREGULARITIES OF THE TEETH. 



III. Maxillary Deformities among the Blind. 

Examinations were made in the following-named institutions for 
the blind : 

Maryland School for the Blind, 339 N. Charles Street, Baltimore, Md. 
Maryland School for the Blind and Deaf and Dumb, North Boundary Avenue, 
Baltimore, Md. 

Kentucky Institute for the Blind, Louisville, Ky. 

New York Institute for the Blind, 9th Ave. and 34th St., New York. 

Total Deformities in the Jaws of the Blind. 



§, 


1 


i 
1 


ll 


.1. 


1. 

m 




•a 

4 

3 


111 

> 




It 


107 

100 


Male. 
Female. 


53 

52 


8 
8 


9 

7 


10 

5 


20 

18 


3 

6 


6 
5 


7 
3 


207 


... 


105 


16 


16 


15 


38 


7 


9 


11 


10 


Per( 


3ent. 


50.7 


7.7 


7.7 


7.2 


18.3 


3.3 


4.3 


5.3 


4.8 



One case cleft palate. 

In the following table are shown the results of the examinations 
of the mouths of the insane : 

Maxillary Deformities among the Insane. 











a 


a 












o 


X 

& 


o 




111 

Hi 




^1 


1^ ■ 

II 

>• 


11^ 


ill 


11 


430 


Male 


394 


10 


4 


2 


18 


12 


29 


3 


5 


270 


Female 


226 


8 


6 


4 


26 


14 


18 


9 


2 


700 




620 


18 


10 


6 


44 


26 


47 


12 


7 



Examinations of the mouths of seven hundred insane patients at 
the Cook County, 111., Insane Asylum and the Illinois State Insane 
Asylum, as shown in the table revealed the fact that only about 12 
per cent, were irregular, the irregularities consisting of protrusion 
of the upper and lower jaws, partial V-, and very few saddle-shaped 



CONSTITUTIONAI. CAUSES. 



81 



arches. The high arch was quite conspicuous among these people. 
Some of these irregularities were due to local causes. These irregu- 
larities were among cases of congenitally insane patients, or patients 
who had become insane early in life. These observations were not 
confined to the hereditary types. 

With few exceptions, insanity does not appear in the individual 
until the skeleton has attained its normal development. There 
were irregularities of the teeth produced by local causes. It is 
probable that a large percentage of constitutional irregularities of 
the teeth could be found in the mouths of inmates of our private 
asylums, where there are more hereditary cases. 

The following table is the result of examination of the mouths of 
children in the Hebrew Orphan Asylum, New York City, by Dr. S. 
Freeman : 



6 

S5 


w 


■3 




a 

'Hi 


&4 




1- 


^1. 
11- 




II 


86 
69 


Male 
Female 


65 
50 


3 
3 


3 

2 


4 
3 


1 


3 

4 


3 


5 

1 


1 


155 




115 


6 


5 


7 


5 


7 


3 


6 


1 


Perc 


^ent. . 


74. 


3.8 


3.2 


4.5 


3.2 


4.5 


1.9 


3.8 





The large percentage of irregularities among these children may 
be due, to a great extent, to consanguinity. 



Deformities of the Maxilla among Children apparently non De- 
fective. 

Dr. Louis Ottofy, in his paper on " The Incipiency of Dental 
Caries," read before the joint meeting of American and Southern 
Dental Associations at Louisville, on August 30, 1888, reported an 
examination of the mouths of 623 children, — 317 males and 306 
females. These children were pupils in the public schools at Grand 
Forks, Dakota ; Lebanon, 111., and Chicago. The following table 
shows the percentage of irregularities : 
6 



82 



IRREGULARITIES OF THE TEETH. 



Age. Irregular. Regular. 

5 p. c. 100 p. c. 

6 9 91 

7 27.5 72.5 

8 43 57 

9 14 86 

10 31.5 68.5 

11 32.5 67.5 

12 25 75 

13 20 80 

14 35 65 

15 28 72 

It will be seen that the largest percentage of irregularities is 
found at the age of eight years. The cuspid teeth are appearing at 
this time, and at least one-half of the irregularities are due to local 
causes. At the age of thirteen but 20 per cent, of the cases showed 
deformities; nature and a judicious use of the forceps had corrected 
many of them. At the age of fifteen, 28 per cent, of the teeth were 
irregular. I venture the opinion that if these examinations could 
have been extended to the age of twenty years the percentage of 
irregularities would have diminished. The development of the 
jaws at this age would allow nature to reduce many of the ab- 
normal conditions. 

The following table shows the results of examinations of mouths 
of one thousand children over twelve years of age, made by myself 



i 


1 


S 
1 


i 

1 


1 


o ^ 

ll 


1 






ill 


II 


396 
604 


Male 
Female 


313 

467 


11 

8 


3 

4 


5 

2 


26 
30 


5 

6 


18 
43 


12 
21 


13 
17 


1000 




780 


19 


7 


7 


56 


11 


61 


33 


30 


Per cent. . 


78. 


1.9 


.7 


.7 


5.6 


1.1 


6.1 


3.3 


3.0 



The difference between Dr. Ottofy's percentages and those shown 
in the above table is accounted for by the fact that in his table both 
local and constitutional causes are included, while in mine the 
many deformities due to local causes are excluded. 



CONSTITUTIONAL CAUSES. 



83 



Nearly all of these cases were residents of Chicago and had been 
attended by the dentist regularly. These irregularities, therefore, 
might be classed as constitutional or developmental, as they could 
not be prevented by the dentist by the use of the forceps. We 
naturally suppose that the majority of the children examined by 
Dr. Ottofy, living as they did in the country, had received but little 
attention from the dentist, — which would account for the presenta- 
tion of more irregular cases than among those examined by me. It 
is possible also that some of those I examined had had slight irregu- 
larities corrected while they were yoUng, thus preventing serious 
complications w^hen maturity was reached. I should expect to find 
quite a difference in the percentage of irregularities in different parts 
of the country. When people are confined in-doors, and do brain- 
work chiefly, as do those living in cities, they are likely to have more 
irregularities than the country people. So also among those living 
in old parts of the country, as the New Englanders, rather than in 
residents of a new part of the country. The following table will 
bear me out in this statement. The examination was conducted by 
Dr. P. N. Moriarty, demonstrator at the Harvard Dental School, 
Boston. The examinations were made in the mouths of those per- 
sons seeking the services of the students, consequently were from 
poorer classes. 



o 








2 ^ 

.2 »s 

11 


O 5= 
•S C3 




> 


$ 




111 


11 


IP 


80 
143 


Male 
Female 


44 
91 


3 

2 


5 

8 


1 

10 


9 

8 


1 

6 


6 

7 


1 

1 


6 
11 


1 
3 




1 


223 




135 


5 


13 


11 


17 


IT 
1 


13 


2 


17 


4 


1 


Per cent. . 


60. 


2.2 


5.8 


4.4 


7.6 


3.1 


5.8 


0.8 


7.6 


1.7 





A comparison between the tables showing irregularities found 
in the mouths of defective persons and those found in the mouths of 
normal persons shows an excess of the former, the ratio being that 
of about 45 per cent, to 22 per cent. Although statistics cannot be 
made to include all institutions, the number examined, thirty-five, 
is sufficiently large to give a fair average, even when due allowance 



84 IRREGULARITIES OF THE TEETH. 

is made for differences of opinion among different examiners. The 
author's observations and examinations in various institutions 
verifies the correctness of these statistics. It may be urged by 
some that those deformed from birth should be ranged under a 
separate head, it being supposed that such persons show the worst 
forms of irregularities. The author's opinion does not coincide with 
this view. Some of the worst forms of irregularities are found among 
persons that become idiots or insane late in life. Likewise very 
defective jaws are found among persons of neurotic tendencies and 
great intelligence, though not deformed, as will be shown later on. 
The tables show that these deformities are found among defective 
persons, like deaf, and dumb, and blind, as well as among idiots, to 
which class of defective persons older authors limit irregularities. 
Recent French authors go even farther and include criminal classes 
among the list. Of course, all statistics furnish data only approxi- 
mately correct, inasmuch as they cannot include all cases; but 
the greater number of cases included, the more nearly correct are 
inductions. 

In the foregoing argument we have taken the stand that irregu- 
larities are more common among persons suffering from malnutrition 
and defective nerve-centres, and are consequently the outgrowth of 
these abnormal functions. To make this more clear, it is well to 
examine the various causes of idiocy, and other forms of deformity. 

Consanguinity in its Eelation to Deformities in General. 

Consanguineous marriages not infrequently result in mental aber- 
rations in the progeny. Dr. Howe states that in seventeen families, 
the heads of which were related by blood and intermarriage, the re- 
sult was fearful. Most of the parents were intemperate or scrofu- 
lous, and some combined both evils, so that it must be admitted 
there were other causes besides consanguinity to increase the proba- 
bility of infirm offspring. There were born in these families ninety- 
five children, of whom forty-four were idiots, twelve others were 
scrofulous and puny, one was deaf and one was a dwarf In 
some of the families all the children were either idiotic or very 
scrofulous and puny. In one family of eight children five were 
idiotic. The commissioners of idiocy in Connecticut found in one 
hundred and sixty cases of idiocy, twenty which apparently resulted 
from consanguineous marriages. Of these, twelve were children of 



1 



CONSTITUTION A I. CAUSES. 85 

first cousins, three of second cousins, one of third, and four of dis- 
tant relations. Dr. Langdon Down found that out of seven hundred 
and fifty-three male idiots thirty-three were the offspring of first 
cousins, three cases of second cousins, and four of third cousins, — in 
all forty cases out of seven hundred and fifty-three, or rather 
more than five per cent. Of the two hundred and ninety-five 
females, thirteen were the children of first cousins, three of second 
cousins, and four of third cousins, — in all twenty among two hun- 
dred and ninety-five, or a little less than seven per cent. His re- 
searches show that in England at least every fourteenth idiot is the 
child of cousins. The majority of cases of idiocy appear at birth, 
and many such may be traced to habits or tendencies of ancestors. 
Often it is difiicult to determine in what generation the germs of 
the disease were planted. Ludwig Dahl, of Norway, in his work on 
" Insanity," shows, by means of a genealogical tree, how an appar- 
ently healthy couple may have children, grandchildren and great- 
grandchildren affected with idiocy and insansity. In reviewing the 
field of possible causes of idiocy, I am greatly impressed by the ap- 
parent influence of consanguineous marriages. Dr. S. M. Bemis, of 
New Orleans, has found, through his examination of statistics sup- 
plied by a number of physicians, that among two thousand seven 
hundred and seventy-eight children, the fruits of intermarriage of 
first cousins, seven hundred and ninety-three were normal ; one 
hundred and seventeen deaf and dumb ; sixty-three blind ; two hun- 
dred and thirty-one idiotic ; twenty-four insane ; forty-four epileptic ; 
one hundred and eighty-nine scrofulous ; fifty-three deformed ; six 
hundred and thirty seven died early. 

Scrofula as a Cause. 

The most common lesion accompanying idiocy is some form of 
scrofula, such as strumous ulcers, skin eruptions, abscesses, enlarged 
and suppurating glands, diseases of the eye and ear, — these diseases 
being quite general attendants of idiocy. A very large proportion 
of all persons affected with idiocy die of consumption of the lungs, 
which is of all diseases most often associated with what may be 
termed a defective make up. Dr. Ireland says that at least two- 
thirds of the idiot class are of scrofulous constitutions. Is arrested 
development of brain-tissue the result of scrofula, or do scrofula and 
idiocy proceed from a common cause ? is a question which is often 



86 IRREGULARITIES OF THE TEETH. 

propounded to physicians. In the light of recent observations, I 
am personally of the opinion that when the two conditions are asso- 
ciated they are dependent upon a common cause ; never in my 
opinion do they bear the relation to each other of cause and effect. 
The teeth, as we well know, are affected in their development and 
growth by scrofula and other constitutional defects. The other 
organs and tissues of the body may not outwardly show such de- 
fects as plainly as do the teeth, but the result of any constitutional 
disease will nevertheless be apt to exist in a form quite as markedly 

pathological. 

Drunkenness in Paeents. 

There is a wide variance of opinion among medical men regarding 
the probable influence of intemperance of parents in the production 
of idiocy and allied conditions in their offspring. Dr. Langdon 
Down is emphatic in his opinion that drunkenness at the time of 
conception is liable to produce serious results upon the brain of the 
child. Ludwig Dahl believes that the abuse of brandy in both father 
and mother is one cause of the large number of idiots in Norway. 
On the other hand, Dr. C. T. Wilber, of the Illinois State Asylum 
for Idiots, states that in three hundred and sixty-five idiotic patients 
eight only claim drunken parents. Dr. Graham, superintendent at 
Earlswood, England, also states that he found among eight hundred 
inmates of that institution but six cases of idiocy which could be 
attributed to intemperance of parents. Whether or not drunkenness 
is responsible for idiocy we cannot decide, but we know positively 
that intemperate habits are transmitted from generation to generation, 
each series of progeny in the line of descent showing a lower grade 
of intellect. As further illustration I cannot do better than quote 
Dr. Shuttleworth : 

'' Considering the intimate and prolonged dependence of the child 
upon the mother during gestation and nursing, one would suppose a 
priori that maternal rather than paternal drunkenness would count 
most in the production of idiocy. In the cases which I have tabula- 
ted, drunken fathers preponderate in a majority of thirteen to four. 
Possibly the mental anxiety entailed upon the wife by a drunken 
husband during the impressionable period of pregnancy may in part 
explain the discrepancy. Whatever the direct effect of drink upon 
the fetus in utero, there is little doubt that such nursing as a child is 
likely to obtain from a drunken mother will intensify any predispo- 



CONSTITUTIONAL CAUSES. 87 

sition to mental defect. The baneful practice of giving infants al- 
coholic drinks seems to prevail to a great extent in Sweden and 
Norway. Such practice may in part account for the extensive preva- 
lence of idiocy and juvenile insanity in Scandinavia, as described by 
Ludwig Dahl." 

Pre-Natal Influences and Intra-Uterine Education. 

It is unquestionably a fact that a fright to a mother during preg- 
nancy is occasionally a cause of idiocy in children. Women instinc- 
tively shrink from anything which would produce a shock or special 
mental impression during the period of gestation, fearing for 
both the mental and physical welfare of the child. Strange to 
say, the same maternal instinct prevails with the brute creation. 

Dr. G. H. Fisher has written a very complete history of the 
*^ Literature, Classification, and Description of Human and Brute 
Monstrosities," including the so-called parasitic monster known as 
^^ Fetus in Fetu," and the jarious supernumerary formations 
of parts and organs which are familiar to medical men. Many 
interesting cases are given by this author, including defor- 
mities of the upper and lower extremities and internal organs. 
He shows that the lower animals may become insane, and that 
heredity and pre-natal shocks have much to do in producing 
these conditions. 

Innumerable cases of pre-natal shocks producing idiocy, where 
the parents were both apparently healthy, are on record. In one 
case the news of the loss of the husband at sea had the effect of 
impairing the intellect of the unborn child. Again, the same result 
occurred in another case as a result of fright occasioned by a team. 
of horses running away with the mother when well along in utero 
gestation. Baron Percy, a French military surgeon, observed that 
out of ninety-two children whose mothers had been exposed to the 
terrors of a tremendous cannonade at the siege of Landau, in 
1793, sixteen died at the instant of birth; thirty-three languished 
from eight to ten months, and then died before the age of five years ; 
and two were born with numerous fractures of the bones of the 
limbs.* 

The authorities for the above are " Medicine in its Relation to the 

* Trans. N. Y. State Med. Soc. 1865-68. 



88 IRRE:aUI.ARITIE:S OF THE TEETH. 

Mind," Dickson ; Griesinger on " Mental Diseases ;" " Insanity," by 
George H. Savage; Ireland's work upon ** Idiocy and Imbecility, ^ 
and the ''Transactions of the Association of Medical Officers of 
American Institutions for Idiots and Feeble-Minded Persons/' 

The result of the various lesions and pre-natal impressions already 
mentioned is not only mental in character, but we invariably find 
arrest of development of brain substance in idiots, imbeciles and 
feeble-minded children, the different terms indicating the degree of 
mental development. It is to be observed that a majority of these 
cases are affected by impressions made upon the fetus in utero 
through the infiuence of the parents. A few cases, however, are 
inentioiied &s resulting from diseases or injuries occurring soon 
after birth or in childhood. If arrest of development of brain- 
tissue occurs in utero or in early childhood, other organs or 
tissues of the body are likely to be similarly affected. The brain 
of the idiot is lighter and has fewer convolutions than the normal 
brain, and also differs in that the convolutions of the idiot's brain 
correspond on both sides, like the monkey's, while they vary in the 
normal human brain. The anterior lobes of the cerebral hemis- 
pheres are imperfectly developed, and where the head is unusually 
small the antero-posterior diameter of the cerebral hemispheres is 
shortened. Irregularity of the two halves of the brain is commonly 
observed. 

The cerebellum, pons Varolii and medulla oblongata are smaller 
than normal with almost perfect asymmetry. Not infrequently 
portions of the brain are altogether absent ; absence of the entire 
cerebellum and a rudimentary condition of one or both olivary bodies, 
peduncles, optic thalami and corpora striata having been noticed. 
Griesinger, in his work on "Mental Diseases," mentions a number 
of interesting cases, one of which we will cite. The brain examined 
was that of a girl seventeen years of age, who presented the highest 
type of idiocy, in conjunction with a generally defective physique. 
The conditions present were very interesting, and may be briefly 
described as follows: The middle free portion of the corpus callosum 
was entirely absent, as were also apparently the septum and the 
middle portion of the fornix. The anterior and white commissures 
of the gyrus fornicatus were decidedly rudimentary. The convolu- 
tions presented an abnormal grouping, and the island of Keil was 
greatly atrophied. Some of the convolutions were entirely absent. 
The lobes of the cerebellum were asymmetrical. 



CONSTITUTIONAL CAUSES. 89 

Dr. A. Wilmarth, of the Pennsylvania Institution for Feeble- 
Minded Children, says, "In six brains, the island of Reil was ex- 
posed through the defective development of the third frontal convo- 
lution ; in four cases on two sides, in two on one side only. In 
eighteen brains six were found where the cerebrum failed to cover 
the cerebellum by from one-eighth to five-eighths of an inch." 

I could quote indefinitely from eminent authorities at home and 
abroad to show that not only are the different structures of the brain 
of the average idiot atrophied and often entirely wanting, but that 
diminution of weight is the rule. Enough cases have been cited to 
give a general idea of the defects in anatomical structure. 

Having determined the constant relation of defective cerebral 
development to idiocy, it remains to be proven whether the defective 
condition is a special one affecting the brain only, or is an integral 
part of the generally defective or mal-development, or at least of a 
general tendency toward such perversions of growth. When we 
take into consideration the fact that the fetus is developed in two 
lateral halves, which may or may not develop harmoniously, and 
may or may not fuse together properly, it becomes logical to pre- 
sume that any influence which tends to produce inharmony and 
asymmetry of growth in one part of the body — e.g , the brain — must 
necessarily tend to produce the same conditions in other portions of 
the fetal halves, providing such influence is not a purely local one. 
The causes of idiocy not being local, but general, the inference is 
obvious. It is astonishing to me that the superintendents of insti- 
tutions for the feeble-minded have made so little note of the asymmet- 
rical relations of the two lateral halves of the body, in the cases 
under their care. Personally, I am of the opinion that harmony of 
members does not generally prevail in the anatomy of the idiot. In 
examining the inmates of various institutions, I was struck with the 
numerous examples of arrested development, hypertrophy and 
asymmetry of upper and lower extremities. These abnormal con- 
ditions accord with the types of cerebral mal-development already 
cited. 

In a paper by Dr. G. E. Shuttleworth, England, presented before 
the International Health Exhibition, London, August 2, 1884, upon 
'"The Health and Physical Development of Idiots as Compared with 
Mentally Sound Children of the same Age," he says : " Many idiots 
are undoubtedly small at birth ; not a few have been brought into 



90 



IRREGULARITIES OF THE TEETH. 



the world prematurely, but in nearly all imperfections of functions 
interfere with due nutrition and development, as the following table 
will demonstrate: 



Table shovnng the Relative Mean Stature and Weight of the General 
Population, and of Twelve Hundred and Nine Idiots and Imbeciles in Earls- 
iDOod, Royal Albert^ and Larbert Asylums. 



Affe 


Height. 


Weight. 


















last 
Birth- 


General Population. 


Idiots and Imbeciles. 


General Population. 


Idiota and Imbeciles. 


day. 


















Males. 


Females. 


Males. 


Females. 


Males. 


Females. 


Males. 


Females. 




Inches. 


Inches. 


Inches. 


Inches. 


Pounds. 


Pounds. 


Pounds. 


Pounds. 


5 


41.0 


40.55 


40.0 


39.5 


.... 


39.2 


39.0 


37.5 


6 


43.0 


42.88 


42.25 


41.25 


. . . . 


41.7 


43.0 


41.0 


7 


45.0 


44.45 


44.0 


43.25 




47.5 


46.5 


45.0 


8 


47.0 


46.60 


45.75 


45.25 


55.0 


52.1 


50.5 


49.0 


9 


49.0 


48.73 


47.5 


47.5 


60.0 


55.5 


55.5 


53.0 


10 


51.0 


51.05 


49.0 


49.0 


65.0 


62.9 


59.0 


59.0 


11 


53,0 


53.10 


51.0 


51.0 


70.0 


68.1 


64.5 


66.0 


12 


55.0 


55.66 


52.5 


53.0 


77.5 


76.4 


70.5 


72.0 


13 


57.5 


57.77 


54.75 


55.0 


85.0 


87.2 


77.0 


80.0 


14 


60.0 


59.80 


56.5 


56.5 


92.5 


96.7 


85.5 


88.0 


15 


62.0 


60.93 


59.25 


58.0 


102.5 


106.3 


94.5 


95.0 


16 


64.0 


61.75 


60.75 


59.0 


117.5 


113.1 


103.0 


102.0 


17 


65.5 


62.52 


62.5 


59.25 


135.0 


115.5 


110.0 


106.0 


18 


66.5 


62.44 


63.25 




142.5 


121.1 


116.0 


108.0 


19 


67.0 


62.75 


63 25 




143.7 


123.8 


120.5 


108.5 


20 


67.25 


62.98 


64.0 


59.5 


145.0 


123.4 


121.5 


108.5 


21 


67.5 


63.03 


64.25 




146 2 


121.8 


122.0 


. . . . 


22 




62.87 


64.5 


.... 


147.5 


123.4 


122.5 


.... 


23 


' 67.75 


63.01 
62.70 
62.02 


.... 




148 7 
150.0 
151.2 


124.1 
120.8 
120.0 






24 






25-30 


64.75 


59.75 


123.0 


109.0 


30-40 










152.5 
155.0 
157.5 


120.8 
118.6 
104.0 






40-50 


' 68.0 * 


61.15 










50-60 























"It will be observed that idiots are shorter than the general 
population, — at five years, by one inch; at ten years, by two inches; 
at fifteen years, by three inches ; at twenty years, by three inches. 
While, as regards weight, male idiots are lighter than the general 
population, — at eight years, by four and one-half pounds; at ten 
years, by six pounds ; at fifteen years, by eight pounds ; at twenty 
years, by twenty-three and one-half pounds; the disparity being 
greater in the male than in the female sex. It appears that the 
relative rate of growth of the two sexes of idiot children follows the 
same rule as that of normal children, and is subject to the same 



CONSTITUTIONAI. CAUSES. 91 

variations at the age of puberty, for two years preceding which the 
growth of girls is in excess of that of boys." 

Abnormally-shaped Heads. 

. If the mental capacity could, in all instances, be measured by 
the size and form of the head, many among the idiotic would rank 
high. The shape and size of the skull are indicative of the mind 
only in a general way, the feeble-minded being about equally di- 
vided between abnormally large and small heads. The measure- 
ment of the ordinary well-balanced head ranges from twenty to 
twenty-six inches in circumference, and that of the idiotic head from 
twelve to thirty-six inches. Opinions vary in regard to the average 
size of the microcephalic idiots, some claiming that all heads of six- 
teen inches and under come under this class, and others that thir- 
teen inches in circumference is the average microcephalic head; 
while on the other hand all heads which measure more than twenty- 
six inches in circumference would be considered either macroce- 
phalic or hydrocephalic. 

The extreme cases are comparatively few in the institutions. Out 
of six hundred inmates of the Pennsylvania Institution at Elwyn, 
which I examined with the assistance of the superintende^t, Dr. I. 
N. Kerlin, and Dr. Wilmarth, I found but tw^enty-eight microce- 
phalic, twenty- four macrocephalic and three hydrocephalic cases. 
We shall find, these extreme cases exceedingly interesting in the study 
of the etiology of irregularities of the teeth, and shall give special 
attention to their relations later. There is a certain size of the head 
below which an individual must be an idiot. Voisin says that " the 
proper exercise of the intellectual qualities is impossible with a 
head of from eleven to thirteen inches in circumference, and a 
measurement of eight to nine inches from the root of the nose to 
the posterior border of the occipital bone." Irregularities in the 
external surface of the cranium predominate in every idiotic head, 
and in such variety that no two heads are found alike. These con- 
ditions show a want of development of the brain. The brain sub- 
stance being the first to obtain its growth, the cranial bones are 
molded about it, and are, in a manner, supported by it until the 
sutures have united. If the brain be slow in developing and shap- 
ing, ossification of the sutures is retarded ; should the brain, or 
parts of it, be retarded in growth, the cranium would be either mi- 



92 IRREGULARITIES OF THE TEETH. 

crocephalic or asymmetrical in its development. Again, inharmo- 
nious closure of sutures may also produce unilateral contractions of 
the bones of the head. I do not wish to convey the idea, however, 
that asymmetry in the cranium is always the result of malformation 
of brain-tissue, as by far the majority of cases result from arrested 
development or interruption in the growth of bone tissue. Per con- 
tra, I am well aware that perfectly symmetrical heads are rare in 
even normal individuals. The diagrams in possession of our hatters 
tell a woful tale, not at all flattering to our racial self-conceit. This 
retarded growth may result from constitutional disturbances acting 
unfavorably upon general nutrition, or from inflammatory condi- 
tions of the osteophytic membrane, which may take place in utero, 
thus prematurely closing the sutures. There is no law governing 
the development of the brain and the closing of the cranial sutures. 
Those bones the sutures of which close before the proper time will 
be narrowed at the point of premature fusion. It is reasonable to 
expect that when bones prematurely ossify at one part of the 
cranium, dilation will take place directly opposite, as the brain 
grows in the direction of the least resistance. This explains many 
peculiar deformities of the head. Again, if the majority of the 
sutures ossify prematurely, microcephalus may result. It appears 
reasonable also to infer that the shape of the basis cranii will be 
affected in a similar manner by too early or too late ossification. 
These changes are caused by improper nutrition of the bones and 
cartilage. A knowledge of this fact gives us a clear conception of 
the relation which various general conditions bear to idiocy and 
imperfect development in general. The influences of such perver- 
sions of nutrition as are produced by syphilis, tuberculosis, struma 
and intemperance over the ossification and growth of bone is a most 
patent one. The shape of the base of the skull and the contour of 
the face depend largely upon the ossification of the sutures. When 
ossification of the cartilages occurs early, a shortening of the basis 
cranii results. Especially is this the case when premature ossifica- 
tion occurs in connection with the sphenoid bone. The age when 
the basilar portion ossifies in a normal subject is from fifteen to 
twenty years. Thus too early ossification naturally produces a short- 
ening in the autero -posterior direction, which causes serious deform- 
ities in the shape of the face, and an abnormal curvature at the 
base of the brain. The superior maxillary bones are attached to the 



CONSTITUTIONAL CAUSES. 93 

bones of the head and face by eight articulations, and as the o^^sifi- 
cation of the sutures occurs at about the same time as the ossifica- 
tion of the sutures of the basis cranii, the same influences which 
affect the cranium must also affect the superior maxilla. These 
conditions may account for family features not presenting them- 
selves until middle age. This is a strong argument in favor of 
postponing the operation of regulating teeth until the contour of the 
face has been permanently established. When there is inflamma- 
tion of the membrane in utero (which is of common occurrence), 
the sutures ossify before or soon alter birth, and as a result the base 
of the cranium will assume and remain in an undeveloped condi- 
tion, causing the face to present an abnormal shape and size, which 
will broaden the face, throw the cheek bones out prominently, make 
the nose broad and flat and sunken, and extend the space between 
the eyes, giving as a whole a face void of expression. When the 
sutures at the base of the skull ossify normally the antero-posterior 
diameter is longer, the base of the cranium is more angular, the 
features sharper, with the eyes closely set. and a face full of expres- 
sion. The sphenoid bone does not attain its full size until from the 
twenty-fifth to the thirtieth year of age. 

I am of the opinion that, when the bones at the basis cranii ossify 
before or shortly after birth, the superior maxilla and septum nasi 
assume a decidedly unnatural form. 

Dr. Oakley Coles, in his work upon " Deformities of the Mouth," 
ascribes the different deformities of the jaw to premature ossification 
either of the sutures or the basis cranii. Thus he sa3's that " the 
deformity known as inter-maxillary prognathism is the result of a 
force operating on the inter-maxillary bone, such force originating 
in the body of the sphenoid, and being transmitted by the interven- 
ing nasal septum." He says also, page 93, "After carefully exam- 
ining the works of various writers on the subject of microcephalic 
idiocy, there seems suflicient evidence to justify the belief that pre- 
mature ossification of the sutures is the rule in a majority of cases 
of microcephalus, and we may therefore assume, if we cannot abso- 
lutely conclude, that this influence operates powerfully in the pro- 
duction of the dental deformity known as the lambdoid jaw " (or 
V-shaped arch). 

While, as has already been observed, I believe that premature 
ossification of the sutures and basis cranii is followed by deformities 



94 IRREGULARITIES OF THE TEETH. 

of the jaw and septum nasi, I do not think that they bear to each 
other the relation of cause and effect. In this I beg leave to differ 
with Dr. Coles. It is unnecessary to expatiate upon this subject 
here, as it will be the principal topic for discussion in another 
chapter. 

We have considered above the morbid influences of various dis- 
orders in producing a vicious condition of the entire system called 
idiocy. It would be erroneous, however, to conclude that this is 
the sole effect of these disorders, nor are excessive and arrest of de- 
velopment limited to idiots, but they may be found in any portion 
of the osseous system, as appears from perusing the literature re- 
ferred to below. 

Bibliography. 

(1) Hutchinson, J. ''Arrested Development of the Radius, Fore-arm and 
Hand." Tr. Path. Soc. London, 1865-6, xvii. 223, 226. 

(2) Leroy. '' Arret de Developpement de I'Avant-bras Gauche." Eevue 
Photog. des Hop. de Paris, 1871, iii. 80-82. 

(3) Rodenstein. " Case of Arrested Development of both Upper Extremi- 
ties." Am. J. Obst, N. Y., 1876, viii. 603-663. 

(4) Shattuck. " Case of Arrested Development and Growth of the Eight 
Upper Limb in a Man." Tr. Path. Soc. Lond., 1881, xxxii. 276-280. 

(5) Cayley, W. "Arrested Development of Forearm and Hand." Tr. 
Ibid., 1865-6, xvii. 430. 

(6) Chipperfield, W. N. " Curious Arrest of Development of the Hand." 
Madras Monthly J. M. Soc, 1873, vii. 409, pi. 

(7) Doran, A. "A Case of Arrested Development of the Bones of both 
Fore-arms ; Extreme Senile Changes in the Osseous Tissues." Tr. Path. Soc. 
Lond., 1876, xxvii. 314, 316. 

(8) Dreyfous, F. " Arret de Developpement du Membre Sup^rieur." 
Progres Med., 1878, vi. 483. 

(9) Foucher. " Excessive Development of Left Arm and Leg." Bull. Soc. 
Anat. de Paris, 1850, xxx. 98, 108. 

(10) Hill, A. " Case of Arrested Development in the Eight Fore-arm 
of . . " Brit.-Am. J. M. and Phys. Sc, Montreal, 1849, v. 119. 



CHAPTER Y. 

CONSTITUTIONAL CAUSES— (Continued.) 

NEUKOTIC TENDENCIES AS A CAUSE OF AKKESTED AND EX- 
CESSIVE DEVELOPMENT OF THE MAXILLA. 

Morel, in his discussion of human degeneracy, points out among 
the evidences of the effect of hereditary defect, abnormalities of the 
jaws and teeth. These were due to cerebral malformation, and 
to this Morel ascribes all other structural defects as secondary. 
These defects have been detected in idiots, congenital epileptics, con- 
genital criminals, congenital paupers, congenital deaf-mutes, the 
congenital blind (in whom teratological defects produce blindness) 
and the hereditary lunatics. Although Morel's researches have 
since the publication of his epoch-making work * been excellently 
supplemented by the work of his pupils : Magnan f in France, 
Kraft Ebing | in Germany, Meynert § in Austria, Spitzka || in 
America and Lombroso ^ in Italy, still these students have devoted 
their attention chiefly to the nervous system, and have discussed 
bodily defects like hare-lip and maxillary malformations only in a 
very secondary degree. Their researches show that the malforma- 
tions occurring in the congenitally deficient classes mentioned are 
the same in origin and result, as the researches of Spitzka and 
Sutton ** demonstrate, from embryological perturbations producing 
excess or defect in development or coalescence in function. Hare-lip 
is a common condition of the second type, as is also the congenital 
edentate condition of which such striking cases are described by Dr. 
S. H. Guilford.ft The " Simian diastema " of the anthropologists, 
found so frequently among the lower races of man by Vogt J{ and 
others, is another instance of the same kind. 

There are other defects due to tropho-neurotic causes such as are 
active in diseases like paretic dementia, §§ locomotor ataxia, multiple 

*Degener. de L'Espece Humaine. 

t Les Folies Hereditaires. J Handbuch der Psychiatrie. 

^ Jahrbiicher f. Psych., Band I. to VI. || Somatic iEtiology of Insanity. 

^ Archivio di Psichiatria, I. to IV. ** Comparative Pathology. 

ft Dental Cosmos, 1882. Xt Lectures on Man. 

g§ Voisin and Mendel on Paretic Dementia. 

95 



96 IRREGULARITIES OF THE TEETH. 

cerebro-spinal sclerosis. These are pathological in character, while 
those first mentioned are teratological or developmental. The field 
of research fii'om an odontological standpoint is a very rich one, but 
has remained untilled by dental scientists. I have therefore taken 
the standpoint that the same laws of pathology govern dental path- 
ology and therefore in the following pages I propose to show that 
the effects of those forms of malnutrition that produce idiocy, deaf 
and dumbness, and blindness, and the malnutrition that results from 
over-stimulation of the brain and nervous system of well-endowed 
individuals, produce similar results, one of the expressions of which 
is arrest of development and excessive development of the maxillary 
bones. 

It is generally conceded that whatever injures the tissues of the 
body injures nerve-struetures, the latter being more vulnerable than 
the former. The first of the intrinsic causes of nervous disturbances 
is hereditary predisposition, which may be either immediate, that is 
transmitted from parent to child, or remote, being derived either 
from a grandparent or some more remote ancestor. The latter of 
these divisions, termed also reversion, is common in this class of 
diseases. An unbalanced nervous system is frequently transmitted, 
carrying with it a predisposition to various diseases. Eoss says, 
" In such cases the tendency to any particular disease is indirect and 
it is also general, inasmuch as one member of the family may suffer 
from neuralgia, another from chorea, paralysis, hysteria, epilepsy or 
insanity, while others manifest a tendency to alcoholic excesses." 

Recent investigation has also shown a tendency to vice or crime 
in some cases. 

Peculiarities of race are a fruitful source of such disturbances. 
Where an irritable nervous system exists, which is stimulated con- 
stantly by improper modes of living, the tendency to such diseases 
is increased. Peculiarities of national life and modern life and 
climate tend in this direction. 

The demands of civilized life grow more urgent while the supply 
of food in proportion to the number of the inhabitants is lessened. 
Excessive desires necessitate exertion out of proportion to strength. 
Our form of government, holding out the bare possibility of rising 
to positions of honor, stimulates effort. Unfortunately, ambition and 
ability are not always balanced, but often in an inverse ratio, desire 
for an object being confounded with the ability to obtain it. It thus 



CONSTITUTIONAL CAUSES. 97 

finds expression in strife for political aggrandizement, social position, 
wealth and culture. The path to political position is strewn with 
physical and moral wrecks, to which occasional newspaper articles 
and records of physicians call attention. These wrecks are not 
more frequent among men than the wrecks produced by the strife 
after social position carried on chiefly by women, the hardships of 
which, though ridiculed by the press, are borne with a fortitude 
worthy of a better cause. Late hours, exposure to cold, alcoholic 
stimulants, opiates and excitement leave traces as disastrous to the 
human frame as want and toil. 

Dr. H. B. Wilbur, in discussing the cause of idiocy, says : " I 
cannot but regard the majority of cases submitted to my care as 
less the result of disease or injury than of ill-nourishment of the 
fetus. Sometimes it is due to the fact that the maternal energy 
is wasted in other directions, as, for example, exhaustive physical or 
mental labor, anxiety or even conforming to the unnatural require- 
ments of modern social life." This can be said especially of the 
mothers among favored classes, whose life is not, as we would expect, 
carried on mostly at home, giving ample time to the family, but is 
frittered away largely in what are termed social duties. 

That the causes of irregularities seen in our offices belong for the 
most part to the favored classes all will acknowledge who are engaged 
in the practice of correction. They are usually young persons of a 
nervous temperament, of slender build, fair or brown hair and deli- 
cate jaws and teeth. In these families the children are usually few 
in number and deficient in force. These children are often descended 
from families the earliest generations of which were robust ; they 
were often men and women of great energy and force of character 
and prided themselves on doing much work. They followed trades 
or lived an out-door life, or followed the professions. Their habits 
were simple, but their descendants, on account of an increase of 
wealth, changed their habits to those of luxury. The toil which 
gives rise to healthy functions was changed to excitement sought in 
amusement alternating with indolence. Gaulton, in speaking of 
energy as a robust virtue and an attribute of the higher races, illus- 
trates the deteriorating effects of indolence by a reference to lower 
animals. He says : " It is a matter of observation that well-washed 
and combed domestic pets grow dull ; they miss the stimulus of 
fleas. 

7 



98 IRREGULARITIES OF THE TEETH. 

" The debt that most countries owe to the race of men whom they 
receive from one another as immigrants, whether leaving their 
native country of their own free will or as exiles on political or 
religious grounds, has often been pointed out, and may, I think, be 
accounted for as follows : The fact of a man having compatriots, or 
so irritating them that they compel him to go, is fair evidence that 
either he or they, or both, find that his character is alien to theirs. 
Exiles are also, on the whole, men of considerable force of char- 
acter. A quiet man would endure and succumb; he would not 
have energy enough to transplant himself or to become an object of 
general attack. We may justly infer from this, that exiles, on the 
whole, are men of exceptional and energetic natures, and it is 
especially from such men that new strains are likely to proceed." 

Such causes have largely been at work in the settlement of this 
country. The Puritans, in fleeing from religious persecution, and 
political and religious exiles of all kinds, formed a large portion of 
our forefathers. They brought indomitable energy, which left a 
goodly heritage to their ancestors. 

But when, as has been pointed out, wealth requires less expendi- 
ture of energy, there is a natural limit to improvement. The 
causes checking unlimited improvement are, increasing delicacy 
of constitution, the growing fineness of limb and structure ending 
in a few generations in fragility. " Overbred animals have little 
stamina ; they resemble in this respect the ' weedy colts ' so often 
reared from first-class racers. One can perhaps see in a general 
way why this would be so. Each individual is the outcome of a 
vast number of organic elements of the most varied species, just as 
some nation might be the outcome of a vast number of castes of 
individuals, each caste monopolizing a special pursuit. Banish a 
number of the humbler castes — the bakers, the bricklayers and the 
smiths — and the nation w^ould soon come to grief This is what is 
done in high breeding : certain qualities are bred for, and the rest 
are diminished as far as possible, but they cannot be dispensed with 
entirely." Another difficulty lies in the diminished fertility of 
high bred animals. 

The principle of division of labor, how^ever profitable to manu- 
facturer, and apparently beneficial to the employee, robs the latter 
not only of a wider sphere of action, but stunts his physical powers. 
Instead of varied healthful labor, one set of nerves and muscles is 



CONSTITUTIONAL CAUSES. 99 

constantly called into requisition, while others are restive under 
enforced inactivity. Irritability of spirit and derangement of 
organism follow. When women and children are pressed into ser- 
vice things become even worse. The body is enfeebled by bad 
drainage and bad air, and consumption, scrofula and infective dis- 
eases follow. In families that have but lately attained wealth it is 
desired that the children shall enjoy the fruits of a higher education, 
and they are consequently subjected to the hot-house pressure of 
schools where they are supposed to acquire a great variety of sub- 
jects. When gifted by nature or coming from families where the 
brain has been trained for several generations, education is 
beneficial to the body. Let, however, the boy or girl of ambition 
and no capacity undertake the same tasks and the results are fre- 
quently disastrous. A deplorable tendency to nervous disease is 
found in those families where for generations scholarship was fos- 
tered and where the physique has become weaker with every 
successive generation until an enfeebled body divests life of plea- 
sure. 

All of these results of the high pressure of our civilization striv- 
ing to dazzle the eye and elicit the admiration of the gaping crowd 
are disastrous to w^ell-being, failing not only in the desire to gain 
happiness but losing also some of the good things hitherto possessed. 
Though disease and enfeebled powers are not apparent in the gen- 
erations engaging in the race, they are visited upon the members of 
the one following. There will be occasional cases of idiocy, 
drunkenness or some other index of feebleness, though the stock 
may blossom out in an exceptional genius, for the want of balance, 
which is the prescribed law of nature, is disturbed. 

The extrinsic causes of neuropathic conditions are mainly lesions, 
excessive exertions, exposures, diseases and physical disturbances. 
Among those of especial interest to us in connection with our sub- 
ject are exposures, excessive exertion and physical disturbances. 
These three are a prominent feature in modern life, being the out- 
growth of competition and unavoidable in many instances. They 
are clearly related in their general effects. Exposures are not con- 
fined to those who work in the open air, such as drivers and the 
like. These frequently escape disease by becoming inured to hard- 
ships, making them less susceptible to changes of temperature. 
The man of sedentar}'' habits is more likely to suffer from slight 



100 IRREGULARITIES OF THE TEETH. 

changes of temperature, because his system is relaxed by over- 
heated rooms and he is exhausted by one-sided exertion. 

Exertion not pushed beyond strength is conducive to health ; 
when pushed to excess, as it often must be, it forms a fruitful source 
of disease The individual that becomes a mere wheel in the 
machinery of a large concern, cannot help suffering from the con- 
stant monotonous tax laid upon him irrespective of his endurance. 

It has been conceded for many years that the condition of the 
nervous system is of the greatest influence on general nutrition. 
Thus Dr. Johannes Miiller, in 1835, makes the following statement : 

" In the embryo in which all organic force is still at rest both 
nerves and organs are produced by the same force. But after 
organs are produced their constant restoration appears to be depen- 
dent on the influence of the nervous system." This reproductive 
power is proved by the fact that several kinds of animals reproduce 
certain parts of their bodies, even late in life, when injured. Spi- 
ders have the power of reproducing a lost limb before they have 
attained full growth. The larvse of insects reproduce their antennae, 
but not so the fully developed insect. Crabs reproduce their legs, 
and fish their fins, and salamanders reproduce their lower jaws. 
That the nervous system is the agent of reproduction of tissues is 
further proven by the effect of a disturbance of nervous centres on 
nutrition. Viering and Langenbuch testify to the influence of the 
emotions in the healing of wounds. Under powerful agitation they 
soon assume an ugly appearance. Everybody knows the influence 
of emotions on the appetite and digestion. Long-continued nervous 
strain has a morbid influence on nutrition, for whatever disturbs the 
equilibrium between nutrition and the exercise of the nervous sys- 
tem opens the door to disease. This want of balance results in the 
deterioration of the osseous system during the period of development, 
which endangers the subject to irregularities of the teeth. Exten- 
sive observation has established the fact that when the brain is weak- 
vened by excessive mental labor or disease, it requires a greater 
amount of phosphoric acid than usual, and this consumption takes 
place at the expense of the teeth and later on at the expense of the 
osseous system. It may be asked, Why should the jaws and teeth be 
affected rather than any other part of the osseous system ? They 
are not more affected, but a slight deviation from the normal 
attracts more attention to these organs, and the modifications the 



CONSTITUTIONAL CAUSES. 101 

contour frequently receives from local causes emphasize these devi- 
ations still further. That irregularities do not appear to be com- 
mon proves nothing. Many are unobserved because they are 
hidden in the posterior part of the mouth and a still greater propor- 
tion are perceived as a part of the face, and are commented upon only 
when the attention is fixed upon them to the exclusion of other 
parts. Sometimes an irregularity is regarded as a habit rather than 
a natural effect, such as vicious anterior occlusion, which is often 
regarded as a failing to keep the mouth closed, and thus these cases 
are not presented to the dentist. 

We have seen in previous chapters that the stock from which 
idiots, imbeciles, deaf and dumb and insane spring is tainted with 
consumption, weak-mindedness, intemperance, syphilis, nervous dis- 
orders, and that irregularities are found to a greater extent among 
these than among persons not defective. 

It is equally true that nervous disorders, such as are fostered 
by an artificial mode of life, increase the tendency to irregularities 
in oflTspring. 

A comparison of the causes inducing neuropathic tendencies 
through excessive stimulation and those inducing a defective organ- 
ism shows them to be analogous in many respects and their results 
are similar. A result common to both is arrest and excessive 
development of the jaws, producing irregularities of the teeth. 



CHAPTER yi. 

FOEMS OF IKEEGULAEITIES EESULTIXG FEOM COlsSTITU- 
TIONAL CAUSES. 

L THE V-SHAPED AECH. 

Irregulaeities of the teeth and jaws resulting from excessive 
development have been described. It remains now to show how 
irregularities result from arrested development. 

Arrest of development is confined mostly to the upper jaw ; hence 
V and saddle-shaped arches are more numerous than irregularities 
of the lower jaw. Local conditions, such as premature extraction 
of the temporary teeth, causing the first permanent molars to move 
forward, thus diminishing the size of the jaw, are also the cause of 
these irregularities. 

The manner of these formations is as varied as the peculiarities 
themselves. 

It may be well at the outset to state that the only structures in- 
volved in the formation of these deformities are the jaws and the 
alveolar process on the one hand, and the teeth upon the other. 
The alveolar process is soft and yielding, while the teeth and jaws 
are composed of hard, unyielding substances. The process 
adapts itself to the conformation of the teeth. We are taught that 
this teeth of the superior or inferior maxilla constitute a dental 
arch, and that the first permanent molars perform the function of 
keys to the arch. After years of thorough investigation I find that 
the jaws and teeth, like the lateral halves of the body, develop in- 
dependently of each other, both possessing their own peculiar char- 
acteristics as regards irregularities of the teeth. In order to sim- 
plify the classification of irregularities of the teeth I shall call the 
lateral halves of the jaws, which are separated by the median line, 
the right and left inferior and the right and left superior dental 
arches. While these terms as applied to the lateral halves of the 
maxillary bones are not strictly correct from an architectural point 
102 



I 



CONSTITUTIONAL CAUSES. 



103 



of view, yet practically (as will be seen) they answer the purposes 
for which they are employed. 

The manner of the formation of the V-shaped arch and kindred 
deformities may be compared to the construction of an arch of stone. 
The changes which take place in the movement of the teeth are very 
similar to those which may occur in a stone arch of faulty construc- 
tion. Figs. 23, 24, 25 represent one normal arch and five varieties of 
irregularities of the teeth. Each lateral arch is viewed as contain- 
ing stones corresponding in number and size with the teeth of a nor- 
mal upper denture. Fig. 23 represents two arches ; the left superior 
arch is perfect. The first stone is marked " posterior base," and 
corresponds to the first permanent molar. The second stone is the 

Fig. 23. 




" anterior base ; " it corresponds to the central incisor. The next 
stone is located upon the anterior base and corresponds to the lateral 
incisor. The succeeding stones are laid upon the posterior base, 
and represent the first and second bicuspids. The stone correspond- 
ing to the first bicuspid is usually in position first, but sometimes the 
stone corresponding to the second bicuspid is placed first To com- 
plete the arch it is necessary to place the " key-stone " in position — 
the' cuspid tooth. If the stones have proper proportions and the 
measurements are correct, the key-stone will fit into place and the 
arch will be complete. We shall find on examining the foundations, 
two more stones, which correspond with the second and third 
molars ; these stones, with the base and the stones above the base, 
make a strong abutment. 



104 



IRREGULARITIES OF THE TEETH. 



The Normal Arch. 

In order that aberrations from the normal may be better under- 
stood, let us first consider the question, what constitutes a normal 
arch. 

There are three characteristics of the normal arch. Independent 
of temperamental peculiarities, the line extending from one cuspid 
to the other should be an arc of a circle, not an angle or straight 
line ; the lines from the cuspids to the third molar should be straight, 
curving neither in nor out, the sides not approximating parallel 
lines. Absolute bilateral uniformity is not implied in this, as the 
two sides of the human jaw are rarely if ever wholly alike. A 
uniform arch necessitates a uniformity of development between the 

Fig. 24. 




arch of the maxilla and the arch of the teeth, and a correct position 
of the individual teeth in their relation to each other. When there 
is inharmony of development between the jaw and the teeth, as may 
happen when one parent has a small maxilla with correspondingly 
small teeth, and the other a large one with correspondingly large 
teeth, if the child inherits the jaw of one and the teeth of the other, 
irregularities must follow. Such difference in diameter between the 
arch of the maxilla and that of the crowns of the teeth is a consti- 
tutional cause of irregularity. 

Whenever there is a difference between these diameters, the line 
formed by the teeth must either fall outside or within the arch of 
the maxilla, and irregularities of arrangement result. 



CONSTITUTIONAI. CAUSES. 



105 



Formation of the V-shaped Arch. 

In Fig. 23 the right superior arch shows the diameter of the stones 
to be either two small for the curve of the arch, or that the bases 
were set too far apart for the curve of the arch. This results in a 
greater space for the key-stone than is required, and not finding 
support it drops through towards the centre line. 

In Fig. 24 the right superior arch shows that the posterior base 
and the foundation stones have been brought forward to such an 
extent that when the other stones are placed in position, the space 
intended for the key-stone is entirely closed and the key-stone re- 
mains outside the arch. The left superior arch appears as though 
the key stone were too heavy for the arch, and its weight has 




carried the smaller stones with it. The posterior base with its 
foundation stones, being the strongest, resists the force ; the anterior 
base being weak and without support, bulges out, and in this way a 
semi- V-shaped arch is produced. 

Fig. 25 illustrates the V-shaped arch. The right superior arch 
shows that the key-stone has gradually carried the arch inward ; 
the posterior base is in its proper position, the anterior base has 
been carried forward, and all the stones are in line. The key-stone 
in the left superior arch has produced the same result as upon the 
opposite side, excepting that the posterior base and the foundation 
stones were placed too far forward, leaving insufiicient space for the 
key-stone. The teeth, however, do not bear the same relation to 



106 IRREGULARITIES OF THE TEETH. 

one another upon their approximal surfaces that the stones of the 
arches do. The stones of an arch have broad, flat surfaces, "while 
the teeth touch merely upon the points of rounded surfaces. 

The ten anterior teeth which are involved in the construction of 
the Y-shaped and kindred irregularities, are illustrated in Fig. 26, 
in which the positions of the roots and crowns, and their mutual 
relations, are approximately shown. As will be observed, the teeth 
are all wedge-shaped, the bases being located near the cutting and 
grinding-edges and the apices at the ends of the roots. These are 

Fig. 26. 




nearly round and conical, the points of antagonism being near or 
quite at the cutting or grinding-edges. Fig. 27 shows a section of 
the teeth at their points of contact. These points must be kept in 
mind, as they constitute the fulcra of the levers, which, when force 
is applied to the teeth, cause them to rotate and move out of posi- 
tion, thus producing a greater variety of deformities than it is pos- 
sible to demonstrate upon the stone arch. 

As has been previously mentioned, these irregularities are 
not observed until after the fig. 27. 

eruption of the second set of 
teeth. We shall therefore 
first consider the first perma- 
nent molars. These teeth are 
the largest, strongest, and pos- 
sess the largest roots of any 
of the teeth. They are lo- 
cated posteriorly to the tem- 
porary set. Owing to their 
position and to the fact that they have long, large roots, their apices 
are directed backwards, and, in a majority of cases, the distance 
from the apex of one root to that of another is greater than at the 




CONSTITUTIONAL CAUSES. 107 

neck, which fact indicates that they are firmly fixed in their alveoli. 
The alveolar process is wide at those points ; these teeth therefore 
would naturally be designated as the posterior bases of the lateral 
arches. 

The next teeth which make their appearance are the central in- 
cisors. These are situated in the extreme anterior alveolar process 
on either side of the median line, and the process is quite thin at 
these points. These teeth will be called the anterior bases of the 
lateral arches. The next to make their appearance are the lateral 
incisors, which take positions at the distal surfaces of the central 
incisors. The roots of these teeth are not so large no^- so long as the 
roots of the centrals ; therefore they are not as firmly fixed in the 
alveoli. Each lateral tooth, however, is supported by the central, 
and represents the second stone upon the anterior base. The 
teeth which next appear are the first bicuspids. Immediately 
following are the second bicuspids, which represent the second 
and third stones upon the posterior bases. The arches are 
then complete, except the key-stones — the cuspid teeth. These 
cannot be omitted, for they bind and hold the teeth together and 
give beauty and shape to the arches. The follicles of these teeth 
are originally situated outside of and above the crown and roots of 
the teeth already in the arch, which results in a larger circle ; and 
because these teeth have long, powerful roots, unusual power and 
leverage is given them. For this reason they are directed down- 
ward and inward, their crowns being so located that the lips assist 
greatly in aiding the downward movement of these teeth. The 
downward and inward movement of the cuspids is similar to the 
lowering of the key stone in an arch ; it continues to move down- 
ward until it meets with an obstruction, which may be confined to 
the upper jaw and include the teeth anterior and posterior to the 
cuspid. If the teeth in position are in harmony with the jaw, the 
cuspids w^ill descend into their proper places and, touching the teeth 
on each side, lock the arches and hold the teeth in proper position. 

Let us examine the arches with their bony encasements, and as- 
certain what the bases are resting upon, the relative strength and 
support of each base, and the relative strength of the anterior and 
posterior columns. In the posterior parts of the mouth the alveolar 
process is very thick, and the base — the first permanent molar — is 
large, having three roots in the upper jaw and two in the lower, 



108 IRREGULARITIES OE THE TEETH. 

curved and so arranged in the alveolar process as to preclude its 
going backward. AVe also find other teeth of nearly equal strength 
posterior to the first permanent molars. Anterior to the base — the 
first permanent molar — we find the first and second bicuspids; these 
teeth are all firmly imbedded and situated in the long axes of the 
alveolar process, forming together a very firm base. The anterior 
column of the arch consists of but two teeth, while the posterior 
column has five. The anterior teeth possess single roots, and are 
situated crosswise in a very thin alveolar process, thus demonstrating 
the comparative weakness of the anterior arch. In some instances 
the space may be too large in the superior arch, and the key-stone 
or cuspid tooth may continue in its downward course till it engages 
with the teeth in the lower jaw. 

Description of the V-shaped Arch and its Modifications. 

Fig. 28. The V-shapcd arch presents a 

triangular outline, Fig. 28, the 
^ apex of the triangle being formed 

\ by the central incisors where the 

\ process is usually bent so that the 

\ incisors form an angle instead of 

\ being in line. From this apex 

\ the lateral halves are in a straight 

\ line terminating at the first molars; 

\ a line connecting them forms 
\ the base of the triangle. The 

* """ cause of this peculiar outline is a 

want of correspondence between the size of the jaw and teeth, or 
the premature extraction of the temporary molar, or both causes com- 
bined, thus allowing the first permanent molars to move forward. 
When the rest of the permanent teeth come in they do not find 
room and are thus crowded together ; the process must give way in 
order to adapt the greater arch formed by the crowns of the teeth 
to the lesser arch of the maxilla. The point of fracture is in or 
near the median line, since the process is thinnest at this point. The 
illustrations given here show varieties of this type. By comparing 
each one with the diagram it will be seen that they all are triangular 
in outline, (Fig. 28c) being the best representation of this form of 
irregularities. A line passing from the median line of the central 



CONSTITUTIONAL CAUSES. 



1C9 



Fig. 28-A. 



Fig. 28-B. 




incisors through the cutting edges and crowns is straight. The 
study of the cases here given shows the result of the forward move- 
ment of the first molar. The subsequent loss of teeth, the peculiarity 
of articulation, and the thinness of the process at certain points de- 
termine the modifications. In Fig. 28-A it will be noticed the 
laterals are gone ; for this reason the centrals are still in line, space 
having been made by the absence of the laterals; Fig. 28-B 
shows by its overlapping centrals that there was want of space at 
the time of their eruption ; the loss of the second bicuspids subse- 
quently, together with peculiarities of articulation, have permitted 
the lateral halves to assume some curvature. Fig. 28-C shows an 
arch too small for the teeth and is destitute of the right first molar 



110 IRREGULARITIES OF THE TEETH. 

and the left first bicuspid. These were evidently lost after the 
central incisors were erupted. The rest of the teeth have migrated 
more or less because not kept in place by close articulation. Thus 
the cuspids are kept out of place, and by their pressure inward 
tend still more to nari'ow the arch anteriorly. In Fig. 28-D the 
centrals are spread, though the process is evidently bent. This 
spreading is accounted for by the absence of the right lateral, which 
has allowed the central to move backward and the cuspid to move 
in. On the left side we see the cuspid erupted inside of the arch. 

Modifications of the V-shaped arch result from modifications of 
the above-named conditions. A difi^erence in the time of eruption 
of the cuspids, everything else being equal, efiects a difierence in 
the space left for their accommodation, and thus partial V-shaped 
arches are found. The key-stone, the cuspid, is not entirely outside 
or inside of the arch in the partial V-shaped form, but may appear 
partially crowded out of place. Hence the arch is neither a normal 
curve nor wholly angular, but unites the characteristics of both. 
Its lateral diameter is less tban'that of the normal arch, giving it a 
contracted appearance. (See Fig. 29.) Thus a number of varieties 
of the fundamental forms of the V-shaped arch are formed, difiering 
in degrees of anterior contraction. All of these result from the 
comparative thinness of the anterior portion of the process offering 
but little resistance, an abnormal pressure from behind, and the 
greater strength of the cuspids, which causes them to seek room 
irrespective of the space left for them. By drawing a perpendicu- 
lar line from the median line of the central incisors to the base, and 
comparing the halves thus obtained with our diagram, we see that 
the right half in Fig. 29-A is partially V-shaped, while the left is 
normal. Kear the apex we have the croAvded condition of the inci- 
sor, overlapping the lateral ; from thence back the curve of the arch 
is lost. The absence of the first bicuspid, together with the want 
of proper articulation, has allowed the cuspid to press nearer the 
centre of the palate than is normal. 

In Fig. 29-B the V-shape is not so apparent, but the central in- 
cisors are crowded, which shows that there is not perfect harmony 
between size of teeth and jaw. This contracts the anterior arch. 

When one side of the process near the symphysis is the stronger, 
thus affording greater resistance, or the pressure of the cuspid is less, 
that side may maintain its normal relations while the other may 



CONSTITUTIONAI. CAUSES. 
Fig. 29. 



Ill 




Fig 29-A, 




Fig. 29-B. 




112 IRREGULARITIES OF THE TEETH. 

give way to cooditions resulting in a V-shaped contraction. The 
curve will then be broken, not at the apex of the triangle, but near 
it ; the incisors will overlap and when pressure from the cuspid 
acts on the weaker column it must give way. This results in the 
semi- V-shaped form. (Fig. 30.) 

Fig. 30A illustrates a semi- V-shaped arch. The teeth in the left 
dental arch are nearly on a straight line. The teeth in the right 
dental arch are situated upon a slight curve. In this arch the 
cuspid is in position, while upon the left arch it is missing. The 
posterior teeth have moved forward and filled the space intended 
for the cuspid. It is still located in the alveolar process, and the 
force produced by the inward pressure of the cuspid is so great that 
the central and lateral incisors have been carried forward and the 
teeth and alveolar process have produced the straight line. The 
lateral pressure of the teeth prevents their being carried farther in- 
ward. The lack of proper antagonism of the central incisors has 
allowed the cuspid to force the incisor and alveolar process forward 
until the basilar ridge of the right central antagonizes with the 
mesial surface of the left central This, in a measure, checks the 
progress of the cuspid inward and holds the arch on a slight curve. 
A perpendicular line drawn from the mesial surface of the right 
central incisor Fig. 30-B to the base shows the left side to be V- 
shaped, while the right is normal. In Fig. 30 C the outline does not 
so clearly point to a V-shaped arch. By comparing the curvature of 
the two halves and noting the position of the right cuspid, it is more 
apparent. The bending of the process at the mesial line is evident 
from the position of the right central. This has turned upon its 
axis from want of lateral antagonism and proper occlusion. This 
partial rotation has allowed the lateral to move back, occupying in 
part the space of the cuspid which has forced the cuspid out of its 
normal position, causing it to erupt outside of the arch. 

Fig. 30-D shows a combination of semi-V and partial V-shaped 
arches. The cuspid being outside of the left arch contracts it and 
gives it the characteristics of the V-shape. On the right side the 
cuspid is partially crowded out of place, and the arch is somewhat 
contracted. 



CONSTITUTIONAI. CAUSES. 
Fig. 30. 



113 




114 



IRREGULARITIES OF THE TEETH. 



Fig. 30-C. 




IRIIEGUI.ARITIES OF THE LoWER JaW. 

The lower jaw never assumes the V-shape when the teeth ar- 
ticulate normally, because the anterior inferior teeth normally 
close inside of the upper teeth, and, while the force from improper 
occlusion of the jaws and the forward movement of the posterior 
lower teeth is as great or greater than the like force exerted upon 
the upper jaw, the forward movement of the central incisors is pre- 
vented by the striking of their anterior surfaces against the posterior 
surfaces of the superior incisors. There are many irregularities of 
the anterior inferior teeth caused by the forward pressure of 



I 



CONSTITU'TIONAI, CAUSES. 115 

the posterior teeth. These are quite difficult to regulate, owing to 
their intimate relations with the superior incisors. The inferior den- 
tal arch should be divided into the right and left lateral arches, 
corresponding to those of the superior arch. The pressure produced 
by improper articulation and the forward movement of the posterior 
columns (the bicuspids and molars) is exerted on each lateral half 
independently, like that in the lateral arches of the upper jaw\ 
Each lateral arch on the lower jaw has its posterior base (the first 
permanent molar), an anterior base (the central incisor), and the 
same number of stones in position upon the bases, — the same key- 
stone, — all representing the same number of teeth as are contained 
in the superior lateral arches. The development of each inferior 
lateral arch is independent of the other, as is the case with the 
superior lateral arches. The irregularities of the teeth in each 
lateral arch are independent of the others. When the posterior 
column moves forward, if the key-stone (the cuspid tooth) is retarded 
or slow in coming into place, the space is filled by the first bicuspid 
and the cuspid remains outside, precisely as in the superior lateral 
arches. If the pressure of the posterior columns and the key-stone 
is uniform, the force will be exerted against the anterior base and 
the first stone upon the base (the central and lateral incisor). In 
this case a different condition exists. The anterior base and first 
stone of the superior lateral arch, and the anterior inferior column, 
resist the force. Occasionally, this is so great that the anterior col- 
umns of both superior and inferior dental arches are carried forward. 
When this occurs, the incisors upon the upper jaw protrude. When 
the forw^ard movement of the posterior column occurs, the incisor 
(or anterior column) will crowd past one another like the sticks of a 
Fig. 31. fan, provided the pressure be uniform 

in both lateral arches. The six teeth 
which are instrumental in the con- 
struction of these deformities are illus- 
trated in Fig. 31. These teeth, as 
will be observed, are wedge-shaped ; 
their points of contact are at their 
cutting edges ; slight oblique pressure will cause these teeth to lap over 
each other. If the pressure is upon one side only, the irregularity 
will be located on that side. One of the common irregularities is 
seen when the key-stone or cuspid tooth is slow in erupting. The 




116 



IRREGULARITIES OF THE TEETH. 



posterior column moves forward and the resistance of the anterior 
column forces the key-stone outside the arch. It sometimes happens 
that the key-stone moves into place and is held in position by the 
anterior column, and the second stone upon the posterior column 
(the first bicuspid) is carried forward outside the arch. This theory 
can be better understood by examining cases of this kind which are 

Fig 32, 




found in my models of the jaws and teeth, and which will be illustrated 
later. It may be well first to glance at Fig. 32, which shows in 
position a section of the teeth made on the line of lateral antagon- 
isms. It will be observed that the mesial and distal surfaces are con- 
vex, and the points of contact are situated at the extreme lateral 
surfaces. If the teeth at eruption should not touch at these particu- 
lar points, or if the force exerted should not be in direct line with 
these j)oints of contact, the teeth would be situated upon an incline, 
and the force thus applied would readily carry the teeth one way or 

Fig. 33. 




I 



CONSTITUTIONAL CAUSES. 117 

the other. Such deformities occur more frequently with the incisor 
and cuspid than with the posterior teeth. The posterior teeth are 
held in position hj their contact with the occluding teeth of the 
opposite jaw, while the incisors do not occlude. One marked feature 
of these irregularities is that in most cases the lateral incisor is 
carried inward and the centrals outward to remain in position in one 
or both lateral arches. These conditions are fully illustrated in the 
chapter on local causes. Fig. 33 shows the right dental arch as 
normal. In the left dental arch the anterior column with the cuspid 
(the key-stone) has moved forward, and the lateral incisor is carried 
inward. This is explained when the relation between the mesial 
surface of the cuspid and the distal surface of the lateral is under- 
stood. In the forward movement of the cuspid the lateral impinges 
upon a markedly inclined plane upon the mesial surface of the cus- 
pid, and the forward pressure carries the lateral inward. Fig. 34 
shows the same irregularity in both right and left lateral arches, the 

Fig. 34. 




pressure being uniform upon each arch. The centrals are also 
slightly rotated in their sockets. This is produced by the flat lateral 
surfaces of the roots meeting and the pressure of the crowns against 
the basilar ridges of the superior centrals. 



CHAPTER VII. 

FOEMS OF lEKEGULARITIES EESULTING FEOM CONSTITU- 
TIONAL CAUSES (Continued). 

II. THE SADDLE-SHAPED AECH. 

The saddle-shaped arch is not so common a deformity as the 
V-shaped. It has many of the peculiarities, however, that are seen 
in the V-shaped arch. It may include one or both lateral arches. It 
may be partial on one side and marked upon the other. It may 
involve the bicuspids and first permanent molars upon one side, or 
but a single tooth on the other. Each lateral arch produces its own 
deformity independently of the other. The roof of the mouth may 
be high or low. The deformity, like the V-shaped arch, is favored 
by the high arch. The following illustration (Fig. 35) shows the 
manner of the production of this deformity. We see here a right 
and left superior lateral arch of stone, each stone corresponding in 
size and location to the natural teeth. The left lateral stone arch, 
corresponding to the left superior dental arch, shoAvs the formation 
of the saddle-shaped arch and the order of laying the stones and 
changing the base. The first stone laid in the arch corresponds to 
the first permanent molar, and, like the stone in the V-shaped arch, 
is denominated the posterior base. The next stone laid corresponds 
to the central incisor, then the stone which stands for the lateral 
incisor. The natural order then changes, and the next stone 
laid corresponds to the key-stone of the V-shaped arch (the cuspid). 
It becomes the anterior base, forming a fixed point in the anterior 
part of the mouth. The next stone laid corresponds to the first 
bicuspid, followed by those representing the second bicuspid and the 
second and third molars. The stones being in position, we find that 
the anterior and posterior colunms are nearly equal in strength and 
resisting power. The anterior column is made up of the anterior 
base (the cuspid), with its long root, backed up by two foundation- 
stones representing the central and lateral incisoi-s. The posterior 
column is made up of its base, the first permanent molar backed by 
two foundation stones, representing the second and third molars. 
118 



CONSTITUTIONAL CAUSES. 



119 



The forward movement of the posterior column takes place in the 
arch from the same causes which produce the forward movement in 
the V-shaped arch. The stone representing the cuspid is not the 
stone involved ; it is almost always fixed in its proper place. The 
weaker stones are those which correspond to the bicuspids, and they 




are the stones which are always displaced when the forward move- 
ment of the posterior column occurs. The change in the crder of 
the laying of the stones — i. e., the stones corresponding to the cuspid 
instead of the bicuspid (it being irregular) — accounts for there 
being fewer saddle than V-shaped arches. The change of the ante- 
rior base will also explain why the anterior column and alveolar 
process do not project, as in the case of the V-shaped arch. The 
right superior lateral arch illustrates another common variety of the 
saddle-shaped arch. It does not differ materially from the left 
lateral arch as regards the order of laying the stones. The anterior 
base is transferred one stone back, the stone corresponding to the 
first bicuspid. The posterior base remains the same. The posterior 
column moves forward and carries the stone representing the second 
bicuspid inward. By comparing the shapes of the natural teeth 
with the stones in the arch just described, we shall observe that the 
approximate surfaces are convex instead of flat like those of the 
stone arch just described. The peculiar incline of the anterior sur- 
face of the first permanent molar and the posterior surface of the 
cuspid tooth, together with the oval shapes of the bicuspids, are 



120 



IRREGULARI'TIES OE 'THE I'EETH. 



singularly well adapted to cause these irregularities upon tlie appli- 
cation of force. The first permanent molars are situated farther 
outside in the arch than any teeth posterior to them. The cuspids 
occupying such a prominent position in the arch, in the anterior part 
of the mouth, the least deviation inward of the bicuspids would give 
the pinched appearance of the jaw at that locality. This deformity 
is caused also by the too early extraction of temporary molars, 
which allows the first permanent molars to work forward and force 
the bicuspids inward, or by the retention of the temporary molars 
or their roots, thus deflecting the crowns of the bicuspids. The 
question arises. Why are not the bicuspids forced outward as well as 
inward ? I would reply that they do occur frequently outside the 
arch : I have several among my collection of models. The inward 
movement, however, is the natural one, because the crowns when in 
the jaw are situated between the roots of the temporary molars. 
The temporary molars are situated upon a smaller circle than the 
permanent molars and cuspids (see Fig. 36). When the temporary 



Fig. 36. 




molars are extracted, the crowns of the bicuspids are in the radius 
of a smaller circle, while their roots have been carried outward by 
the development of the jaw and alveolar process. 

The molars in the saddle and semi-saddle-shaped arches of the 
upper jaw frequently diverge laterally. If the case shows a semi- 
saddle-shaped arch, the divergence is on the side of the deformity^ 
If both lateral arches are involved, both sides diverge. Cases having 
the deformity most prominently have the most marked divergence. 



CONSTITUTIONAL CAUSES. 121 

When a slight change exists only at the bicuspid region, the diver- 
gence in the molar region is slight. This peculiar arrangement of 
the molar teeth may be due to two causes. First, the teeth upon 
the lower jaw diverge on account of the shape of the inferior max- 
illa ; the farther removed from the incisors, the greater the distance 
between the molars of the opposite side. The molars upon the upper 
jaw usually articulate with those upon the lower jaw. The disparity 
in the appearance of the normal position of the teeth and those 
above described is due to the pinched condition in the bicuspid and 
first molar region rather than to the position of the molars. Second, 
when the arch is contracted at the bicuspid region the tongue is 
limited in its movements. In swallowing, the tongue goes to the 
roof of the mouth and is then forced backward for lack of room, 
thus shortening and consequently broadening its surface. The result 

Fig. 37-A. 



Fig. 3' 




of the lateral expansion would naturally be to force the teeth and 
alveolar process outward. 

The position of the temporary molars determines the position of 
the bicuspids. This position shows the diameter of the jaw early 
in life. From that time until the eruption of the third molar, 
L e., from the third to the twentieth year — the jaw has an opportunity 
to develop, which naturally carries the alveolar process and teeth 
out laterally, causing the crowns of the third molar to face the cheek 
in some instances. 



122 



IRREGULARITIES OF THE TEETH. 



Description of the Saddle-Shaped Arch and its Modifications. 

When there is harmony between the size of the teeth and that of 
the arch, and the permanent bicuspids erupt under favorable condi- 
tions, so that their greatest diameter is in a line with the greatest 
diameter of both cuspid and first molar, they will be held firmly in 
place, since the greatest pressure is on this very line. On the other 
hand, when the bicuspids are erupted after their proper time, while 
the cuspids progress duly, the cuspids, meeting with no resistance, fall 
into their natural position, while the bicuspids erupt inside of the 
arch, forming an angle. This angle results from two causes, — ^the 
thinness of the process at this point and the diminution of resistance 
which must follow. 

Fig. 3 7- A shows a decided saddle-shaped arch. The maxillary bone 
is too narrow at its anterior extremity for the teeth, which are suited 
to a more expanded jaw. The constitutional tendency to this defor- 
mity is quite apparent in this case. The vault is high and narrow. 
The first molars are pushed forward, leaving only sufficient space on 
each side for one bicuspid. These are therefore turned inward to- 
ward the palate, making the vault at this point still narrower than 
it naturally is. 



Fig. 38. 



Fig. 38-A. 




When the unfavorable conditions that result in the saddle-shaped 
arch are not so pronounced, we have the partial saddle-shaped arch. 
Thus, because of the greater uniformity of the maxilla and of the 
arch of the crowns there may be more space, and the bicuspids may 
be forced but little out of place, or the molar may move forward but 



CONSTITUTIONAL CAUSES. 



123 



slightly, interfering less with the bicuspids. Sometimes it happens 
that in trying to adjust themselves to the limited space one bicuspid 
may be crowded outward and another inward. Sometimes the first 
bicuspid is in, more frequently the second. (Fig. 38-A). 



Fig. 39. 




Fig. 39-A shows a normal arch on the left side, and a saddle- 
shaped arch on the right. The vault is normal in this case ; hence 



Fig. 39-A. 



Fig. 39-B. 




there is more room for the erupting bicuspids, and less curs^ature re- 
sults than is found in Fig. 38-A. Fig. 39-B shows a similar condi- 
tion of the left side. 



124 



IRREGULARITIES OF THE TEETH. 



Combination of V and Saddle-Shaped Arches. 

How the V-shaped and saddle-shaped arch on one side only may- 
be produced has already been described. How they may be com- 
bined on one side remains to be explained. Given thinness of pro- 
cess in the anterior part of the mouth, premature or tardy extraction 

Fig. 40. Fro. 40-A. 




of the first molar, and there will be a forward movement of the 
incisors. The development of the cuspid will press the alveolar 
process inward, thereby contracting the arch, and the tardily 



Fig. 41- a. 




erupted bicuspids will adjust themselves to the limited curve as 
before stated. In this way the features of the two forms are com- 



CONSTITUTIONAL CAUSES. 



125 



bined ; that is, a contracted or angular anterior arch, and a poste- 
rior arch that is more or less concave. The opposite side may be 
V-shaped, saddle-shaped or normal. (Figs. 40 and 41.) 

Fig. 40-A shows a combination of V and saddle-shaped arch on the 



Fig 42 




left side and V-shaped on the right. Fig. 41 -A is a case of semi-V 
and semi-saddle-shaped arches combined. 

Fig. 42 shows a semi-saddle shape in the right lateral arch, the 
second bicuspid has been forced inside the arch. The opposite side 



Fig. 43. 




shows a condition exactly reversed. The points of lateral antag- 
onism of the second bicuspid are outside the long diameter of the 
dental arch. The anterior movement of the posterior base forced the 



126 



IRREGULARITIES OF THE TEETH. 



tooth outward. The tendency of this irregularity was to form the 
V-shaped variety. The irregularity of the left lateral arch (Fig. 43) 
is a common one. The teeth develop normally, but the second bi- 
cuspid is either retarded in its development or it is deflected inward 
by some local cause. The anterior base is, in this case transferred 
to the first bicuspid. The posterior and anterior bases come together, 
and the second bicuspid is crowded inward. This irregularity cor- 
responds to the right lateral stone arch of Fig. 35. 

The Saddle-Shaped Arch of the Lower "Teeth. 

The saddle-shaped arch on the lower jaw is generally due to 
local causes, the retention of the temporary molars being one of 
them. The one illustrated is the result of both local and consti- 
tutional causes. 

Fig. 44 illustrates a saddle-shaped irregularity upon the lower 
jaw. The impression is from the jaw of a man fifty-six years of age ; 
the second molars were extracted at the age of twenty-two. The ir- 
regularity was produced at the time of the development of the teeth. 

Fig. 44. 




The teeth are large and firmly set in the powerftil jaws. Asym- 
metry of the jaws exists. If they had developed in unison, this 
deformity would have been prevented. The forward movements of 
the posterior columns have carried the cuspids forward and the 
lateral incisors inward, so that the cuspids and centrals stand on 
a line. The second bicuspids and first permanent molars have 



CONSTITUTIONAL CAUSKS. 127 

been forced inward by the inclined plane formed by tbe poste- 
rior surfaces of the first bicuspids, and also by the articulation of 
the superior teeth, which form a smaller arch than the lower teeth. 
As will be seen, the third molars have moved forward and nearly 
filled the spaces made vacant by the extraction of the second 
molars. This forward movement was no doubt due to improper 
articulation with the upper teeth. 



CHAPTER yill. 

LOCAL CAUSES. 

A LOCAL cause resulting in an irregularity is found in malposition 
and malocclusion of individual teeth as a result of an accident, such 
as premature or tardy extraction of temporary teeth, or malposition 
and malocclusion growing out of constitutional causes. 

Before taking up each form of the irregularity to which an indi- 
vidual tooth is subject, a few words should be said about the relative 
influence and force of teeth, for on this these irregularities in a great 
measure depend. 

Relative Importance of Individual Teeth in Effecting 
Ieregulaiiities. 

Foremost in influence on the relative position of permanent teeth 
is the first molar. If the temporary molar is extracted prematurely 
the forward movement of the posterior column follows it, the expanse 
of the anterior column producing more or less vicious position, rela- 
tion and occlusion. I have frequently observed the anterior move- 
ment of the temporary molars and cuspids as well as the permanent 
bicuspids and cuspids, from the great force exerted by the first perma- 
nent molar, and have a number of models showing same. To this even 
the cuspid must yield, though most influential in the anterior column. 
Next to the first permanent molar in importance is the cuspid. It 
asserts itself above the rest because of its vital force, length of root 
and peculiar shape. The length of its root allows it to deviate more 
than any other tooth from its original position, because, with the same 
degree of pressure brought to bear on or near the apex of its root, a 
tooth may diverge in proportion to the length of its root ; though 
the angle is the same, the divergence grows greater the farther the 
cusp is from the apex. 

The central incisor comes next in importance, and then the lateral. 

The central incisor finds a support in its fellow on the opposite side, 

while the lateral is the most passive of teeth. It, however, plays the 

part of a co-ordinating force, since without this wedge the teeth are 

128 



I.OCAL CAUSES. 129 

not retained in their position, and occlusion is disturbed. Because 
of its weakness and short root it is very easily displaced. 

THE CENTEAL INCISOE. 

Irregularities Produced by the Malposition of Central Incisors 
Resulting from Flexion of the Alveolar Process. 

I. In the chapter on general classes of irregularities the fact was 
emphasized that the forward movement of the posterior column — i e., 
the bicuspids and molars due to premature or tardy extraction — will 
force the weaker anterior column and alveolar process forward. The 
pressure brought to bear upon it from both sides makes the arch of 
the upper maxilla greater than that of the lower. As a consequence 
occlusion will be wanting or defective and flexion must take place 
according to the position assumed in the eruption of each individual 
tooth. This condition is greatly promoted by the pressure of the 
cuspids, which, in coming down, assert themselves at the expense ot 
the Aveaker incisors. But this is not alL Much depends on the size 
and the development of the germs of the permanent incisors. When 
there is strong vitality their size may be out of proportion to that of 
the alveolar process. Owing to healthy nutrition or the nature of 
the food that is taken into the system during the time of their devel- 
opment, the centrals may become very vigorous. This more than 
ordinary development shows itself not so much in the relative posi- 
tion of the axes, but in the irregularities of the cutting edges owing 
to the excessive diameters of these, which causes them to over- 
lap slightly. When a temporary incisor persists too long in its 
socket, the germ of the permanent tooth is embarrassed in its erup- 
tion. The germ seeks its way out as best it can, and as ^^I'ojecting 
in a straight line is out of the question, it slips around the temporary 
teeth and is forced partially out of position. The process in this 
case is not unlike that of the germ of a plant that forces its way 
out from under a stone. 

(a) Having considered the cause ^^' ^' 

of the irregularities of this division, 
we will now proceed to consider its 
varieties. A form frequently met 
with is found in V-shaped arches. 
The central incisors are crowded 
together so that their cutting edges are not in a line, but form an 




130 IRREGULARITIES OF THE TEETH. 

angle that points forward. (Fig. 45.) This is the most natural form 
for the flexion to assume. The arch is simply broken in front, follow- 
ing the the general direction of the pressure. The mesial surfaces are 
parallel ; the anterior angle points forward, following the general law 
of incisors. The force is uniform. Had the anterior column not 
been forced forward by the posterior one, these teeth would be nor- 
mal in every respect. Sometimes we find them overlapping each 
other slightly, and occasionally the anomaly is met with that the 
general axes of the teeth do not converge, but diverge. This diverg- 
ence is found to be due to a faulty occlusion, the lower incisors acting 
as a wedge driving the upper incisors apart, or else, from a want of 
occlusion, they follow their course without guidance and support. 

(6) In the second class, where the cutting edges form an angle 
which is directed backward (Fig. 46), the pressure from behind by 

the posterior column has met with 
an obstruction in front. This ob- 
struction exists in the centre of the 
alveolar process, and is strong enough 
to resist in a measure the pressure 
from behind. Hence the force spreads 
itself on the lateral divisions of the 
anterior process. The result is that the mesial line is formed behind 
the distal line, and an angle is formed. Here, as in the former case, 
occlusion is an important factor in determining the position of the 
axis. A want of proper occlusion may force the anterior teeth 
apart. The laterals also in seeking their natural position may help 
to force the distal surfaces of the central incisors still more out of 
line. Being wedged in between centrals and the cuspid teeth, the 
latter, by their greater force, cause the centrals to yield to the laterals 
that are wedged between them. The mesial angle of the laterals 
infringes upon the inner surface of the distal angle of the centrals. 
These continue to rotate until the entire mesial surface of the laterals 
rests against the palatine surface of the centrals. Then the rotation 
naturally ceases, the laterals forming an abutment. Pressure being 
exerted on both centrals, in this way an angle is formed, and the 
pressure on both sides being equal, they are not thrown out any farther. 
The direction of the cutting edges depends on the shape of the teeth. 
If the diameters of the cutting edges exceed much those of the 
necks, they necessarily overlap to a greater extent. 




I 



I.OCAI. CAUSES. 



131 



Fig. 47. 




(c) When the two central incisors do not erupt harmoniously, one 
overlaps the other. (Fig. 47.) If, in addition to this condition, the 
force that is brought to bear on the anterior alveolar arch is very- 
unequal, certain modifications occur. An unequal pressure exerted 
by the cuspids in their eruption will force one side of the arch far- 
ther forward than the 
other. When the first 
molar on one side has 
been extracted, while 
that on the other side 
remains, the forward 
movement is necessarily 
one-sided, and a corres- 
ponding irregularity fol- 
lows. The tardy extraction of temporary teeth goes far in forcing 
the germs of the permanent teeth out of place. Irregularity in the 
lower incisors through faulty occlusion modifies greatly the direction 
of the upper teeth. 

(c?) Sometimes centrals projecting in a line in front of the laterals 
are met with. (Fig. 48.) In this case the centrals erupted properly ; 
but the arch being undeveloped, there is not room for the laterals. 
These are carried forward by the posterior column and in by the 
cuspids, and are possibly driven in by 
the lower incisors, which, instead of 
striking within them, strike without 
exaggerating the difiiculty. When 
this is not the case, and the laterals 
strike outside of the lower teeth, the 
upper arch is too large for the lower, and the upper centrals, not find- 
ing the proper support below, are forced out in a similar manner. 

(e) A similar condition is that in -pia. 49. 

which the central incisors strike 
within the laterals. (Fig. 49.) The 
cause is the same ; but the laterals 
in erupting fail to find the proper 
support and project outward, while 
the centrals occlude properly. In 
this case the upper maxillary arch is not necessarily too large for the 
lower ; but the teeth are crowded. 



Fig. 48. 





132 



IRREGUI.ARITIES OF THE TEETH. 



(/) One form of irregularity that is occasionally met with is that 
which gives rise to a right angle in the region of the cuspids, the 
incisors being in a straight line. (Fig. 50.) There are, of course, 
cases of this kind where the upper and lower arches resemble each 
Fig. 50. Other, and where the occlu- 

sion is fair, which, for these 
reasons, cannot be classed 
under irregularities. When 
this rectangular appearance 
is found in the upper jaw 
only, it is e^ddently due to 
flexion in the region of 
the cuspids caused by the forward movement of the posterior col- 
umn. The anterior alveolar column will be found thick, and is 
therefore capable of resisting the pressure of the posterior column, 
and the pressure is spent on the weakest point, i. e., the region of the 
cuspid. Hence the flexion at this point. There is always an exces- 
sive development of the upper jaw and alveolar process. This 
causes the teeth to erupt too far forward for occlusion with the 
lower arch, and the lip draws them in until they strike the lower 
arch, and the long axes of the teeth point inward instead of out- 
ward. Thus the vault is brought forward, leaving the lower incisors 
without support. 




Irregularities Produced by the Malposition of Central 
I^X'ISORs DUE to Vicious Eruption. 

(a) The laws that govern the eruption of the teeth and harmo- 
nize their development are occasionally interfered with. The germs 
that should be directly over the temporary incisors may be displaced. 
These should be situated above and anterior to the temporary teeth ; 

but occasionally the germ is sit- 
uated above and deflected poster- 
iorly, and thus it is liable to be 
erupted on the palatine surface. 
A displacement of the germs 
generally results in vicious erup- 
tion ; for however slight it may 
be, as the tooth progresses, the 
line of its axis must diverge more and more from that of its normal 



Fig. 51. 




LOCAL CAUSES. 133 

position. The central incisors spring from a point farther back than 
it should be. If the elevation of the gum is followed, it will be seen 
that these two diverge more and more toward their cutting edges. 
Thus the relation of their axes is changed entii:ely, and a partial 
rotation is produced. (Fig. 51.) 

Again, if the roots of the temporary teeth persist instead of being 
absorbed as the permanent teeth advance, they materially interfere 
with the eruption of these, and are apt to turn them out of their 
course. AVhen one of the conical roots of the incisors infringes upon 
another not in the same line, as the teeth develop, a tendency to 
rotation is established on the principle of the scrcAV. This partial 
rotation upon its axis is more apparent the greater the diameter of 
the tooth ; for the cutting edge, usually in line with the other teeth, 
now partakes of the revolution of the axis, and so forms an angle 
with the arch. 

In these three cases, when the tooth is fully erupted it finds a 
proper resting-place on the opposing tooth, its malposition may be 
corrected by the exercise of its proper function ; but it often fails to 
find this, and projects out, being without support. 

(6) Adventitious germs appear occasionally in the alveolar pro- 
cess. When these are found in the arch, they necessarily disarrange 
the occlusion and throw the teeth out of their proper position. Su- 
pernumerary teeth usually appear at the median line, and then ne- 
cessarily crowd all the teeth laterally. Frequently one supernume- 
rary tooth is found exactly in the median line and centrals coming 
down to the right and left in the arch. 

Occasionally two are found in the position where the centrals 
should be. In such cases the cen- yig. 52. 

tral incisors are generally located 
outside and anterior to the lateral 
incisors. When a supernumerary 
is found outside of the arch in the 
median line, one central may be in 
position, the other may be thrown 
out or in, and may be rotated 90° upon its axis. (See Fig. 52.) 




134 IRREGUI.ARITIES OF THE TEETH. 



Irregularities Produced by the Malposition of Laterals. 

1. Mesial surface of lateral overlapping distal surface of central, 
while distal surface is in a line with cuspid. 

2. Mesial surface of lateral overlapping distal surface of central, 
while distal surface is behind the cuspid. 

3. Mesial surface of lateral behind the distal surface of the cen- 
tral, while the distal surface is in a line with the cuspid. 

4. Lateral in a line anterior to that of central and cuspid. 

5. Lateral in a line posterior to central and cuspid. 

6. Lateral at right angles with the line of the incisor and cuspid. 

7. Lateral wholly inside the arch. 

The lateral is found more frequently out of position than any 
other tooth because it is the weakest tooth in the arch and has the 
shortest root, and is therefore more easily displaced. 

We have seen that the position of the central incisor is the com- 
bined result of the relative strength of the alveolar process, the force 
brought to bear upon it by the posterior column and the cuspid, and 
the peculiarities of occlusion. The lateral, on the other hand, 
depends for its position on the combined force of central and cuspid. 
Like other teeth, each lateral depends upon the environments of its 
own side of the arch, independent of the other. Besides its weak- 
ness, two other conditions are productive of its change of position, 
(1) The shortness and conical shape of its root, (2) Its wedge-shaped 
crown. The shortness of its root, together with its conical outline, 
cause it to be more easily impinged upon by the root of the incisor, 
which will i^roduce partial rotation. The wedge-shape of its crown 
facilitates rotation. The greater the diameter of the cutting-edge in 
proportion to that of the root, the greater the degree of rotation must 
be before the lateral finds a resting-place. If the diameter were equal 
to the space left, and there were no impinging on the root, there would 
be no displacements. But when the space is not sufficient for the 
lateral and a pressure is brought to bear on one side of either cutting- 
edge or root, there must be a partial rotation which is proportioned 
to the diameter of the cutting-edge. The wedge-shaped character of 
the crown assists in rotation, as the rounded angle of the anterior cusp 
offers less resistance than a line or surface. This gives rise to the com- 



I.OCAL CAUSES. 



135 




monest form of irregularity (1 and 2, Figs. 53 and 54), in which the 
mesial surface of the lateral overlaps the distal surface of the central, 
while the distal surface of the lateral 
is either in a line with the cuspid or 
just back of it. 

3. In those cases where the lateral 
is in a line with the cuspid, (Fig. 55) 
but its mesial surface behind the cen- 
tral, the cuspid, having a much 
broader mesial surface, affords a firm 

abutment to the movement of the lateral, while the mesial surface 
of the latter easily glides over the narrow rounded distal surface of 
the central incisor. In this 

case the relative diameter ^^^' ®*' 

of the upper and lower max- 
illae determines the occlusion 
and position in a measure. 
If the lower maxilla and 
the upper are properly pro- 
portioned the lower incisor 
may strike in front of the 
upper. 

4 and 5. Laterals not finding room in the anterior column are met 
with in a line in front of that formed by the central and cuspid, (Fig. 




Fig. 56. 





Kifr^ 



56) or behind it (Fig. 57). In both cases there is no rotation produced 
by a one-sided pressure either upon the root or cutting-edge. Whether 
the lateral is found without or within the line depends upon the 
relative diameter of the upper and lower maxill?e and occlusion. 
If the proper relation exists and the lower incisors strike within the 
upper, the upper laterals will be found outside the arch. When the 
diameter of the upper arch is greater than that of the lower, its 
laterals may be found within the line of the centrals and cuspids. In 



136 



IRREGULARITIES OF THE TEETH. 



this case the lower incisors must either strike over the upper, which 
occurs when there is a proper relation of diameters of upper and 
lower maxillae, or else they may strike behind the upper laterals, 
which can occur only when the upper arch has a greater diameter 
than the lower. 



Fig. 57. 



Fig. 58. 





6. A rotation of 180°, so that the lateral is at right angles with a 
line passing through centrals and cuspids, can occur only when 
there is no obstruction to the movement of either root or cutting- 
edge and where thei'e is no proper occlusion. (Fig. 58.) 



Fig. 59. 




7. Occasionally a lateral is found wholly inside of the arch. The 
cause is twofold. Sometimes the lateral is erupted so tardily that 
the cuspid pushes it out of its place. Then, again, even though it 
is erupted, in due time the greater relative (Fig. 59) size and 
strength of the cuspid may crowd it toward the palate. 



1 



CHAPTER IX. 

LOCAL CAUSES— (Continued). 

IRREGULARITIES PRODUCED BY THE MALPOSITION OF THE CUSPIDS. 

The cuspid is the most important tooth in the anterior part of the 
mouth in regard to durability and influence on expression. It owes 
its durability to the hardness of its tissue, slowness of its develop- 
ment and simplicity of shape. The absence of sulci lays it less open 
to the inroads of caries. The pyramidal shape of its cusp gives it 
great power of resistance. Its strength depends on these condi- 
tions and the length of its root, which exceeds that of any other 
tooth. Owing to the length of its root its cusp may move farther 
from its normal axis without really forming a greater angle with it. 
It is placed at the angle between the anterior and posterior columns 
forming the key-stone ; hence it is of the greatest importance in affect- 
ing expression. The shape of the crown may vary from the agreea- 
ble rounded outline of beauty to the prominence of the tusk of a 
wild best. The limits of variation of form and position thus being 
greater than those of any other tooth, it attracts more attention and 
does more to help make or mar beauty. The deviations from its 
normal position may be due to malposition of the germ or crowding 
out of place. It is difficult at times to determine which of these 
causes produces the irregularity, though generally it is clear. 

When no source of pressure upon the erupting tooth can be recog- 
nized, such as is the case when the cuspid erupts in the vault, it is 
safe to assume the former. 

In both the deciduous and permanent set, as compared with other 
teeth, the cuspids are late in erupting. In both it must seek its way 
between two teeth already erupted ; hence its liability to be forced 
out of place. 

The permanent cuspid rarely erupts before the twelfth year 
after the centrals, laterals and bicuspids are in position. It is 
crowded, and therefore meets with obstacles in its descent. Its crypt 
is placed above and in front of those of the lateral and bicusj^id. As 
at the age of nine the roots of the incisors and bicuspids are pretty 

137 



138 IRREGULARITIES OF THE TEETH. 

well calcified, the cuspid may be materially hindered in its eruption 
by these when there is a lack of space. Its conical root makes it 
yield easily to pressure, and its cusp glides readily over the roots of 
the adjoining teeth. If the relation between the calcification and 
decalcification of the temporary teeth does not take place simulta- 
neously a new factor of disturbance arises, for by the pressure of an 
additional obstacle, in the shape of a remaining portion of the root 
of a deciduous tooth, the cuspid may be thrown out of its course, 
while a too rapid absorption of a deciduous root leaves the column 
of resistance broken, thus opening a new channel for the erupting 
tooth. 

The position of its crypt above and in front of those of the lateral 
and bicuspid accounts for the most common form of irregularity, i. e., 
being outside of the arch and above the other teeth. The tendency 
of the cusp is necessarily forward, because the combined force of the 
bicuspids and the first permanent molar from behind is greater than 
that of the lateral in front ; hence the lateral is easily pushed out of 
place. Besides, the roots of all teeth naturally pointing backward 
would give it this tendency. 

When in its normal position the cuspid pushes its way between 
the roots of the lateral and bicuspid, and thereby spreads the arch, 
giving it a parabolic outline and forming a key-stone ; but when it 
remains outside of the arch, the expanded contour is lost and a 

Fig. 60. Fin. 61. 




pinched condition results in the shape of a V-shaped arch. The ad- 
ditional pressure of the cuspid upon the region of the lateral only 
increases this tendency. The cuspid when out of place is usually 
found above and outside of the lateral and bicuspid, this tendency 
being given by the position of its germ and its calcification being 
late as compared with other teeth. (Fig. 60.) 



LOCAL CAUSES. 



139 



One or two cuspids may be found erupted in the palatal vault 
when there is a malposition of the germs. (Fig. 61.) Occasionally 



Fig. 62. 




it is found outside of the first bicuspid or between the first and second 
bicuspid, sometimes in front or anterior to the lateral. (Figs. 62 



Fig. 63. 




After Wilson. 



and 63.) Frequently it takes the place of the lateral. (Fig. 64.) 
Sometimes one cuspid is found in the palate while the other is on a 



Fig. 64. 



Fig. 65. 





line pointing inward. (Fig. 65.) When it comes through in this 
position the deciduous cuspid may still be in position, the first bicuspid 



140 



IRREGULARITIES OF THE TEETH. 



having crowded forward to the lateral. (Fig. 66.) Occasionally 
when the cuspid is missing, the lateral Avill drop backward. (Fig. 



Fig 




After Wilson. 



67.) Its usual position when in the palate is inside the lateral incisor, 
but sometimes it is embedded in the hard palate. A pinched con- 



FiG. 67. 




After Wilson. 



Alter Wilson. 

dition in the bicuspid region necessarily results from such malpo- 
sition, owning in part to the want of prominence of this tooth when 



Fig. 68. 



Fig. 69. 





in its normal position and in part to the inward pressure of the cus- 



1 



LOCAI. CAUSES. 141 

pid upon the bone-cells. (Fig. 68 and 69.) When the cuspid moves 
out of position it does so at the expense of the first bicuspid and 
lateral incisor. The force may be so great as to push the lateral 
forward and through the alveolar process. When the cuspid is 
found in the roof of the mouth, or out of its normal position, the 
posterior column moves forward, filling the space usually occupied 
by the cuspid, (Fig. 64), and the half of the arch of which this tooth 
is a member remains undeveloped. (Fig. 68.) If the cuspids erupt 
simultaneously the pressure exerted is uniform, and there is less 
liability to irregularity. One may erupt normally while the other 
may be abnormal in position. 



Irregularities Produced by the Malposition of Bicuspids. 

The shape of the crown of the bicuspid particularly endangers it 
to irregularities of position. The antero-posterior diameter of its 
outer cusp is greater in proportion than that of the inner, having a 
wedge-shaped space on the palatal side. This causes it to touch at 
one point the tooth in front and back of it, and makes rotation upon 
its axis easy. Irregularities are chiefly limited to the second bicus- 
pid for reasons that become apparent when we consider their causes. 

Like irregularities of other teeth, irregularities of bicuspids may 
arise from constitutional causes, i. e., from a lack of accord between 
the size of the jaw and that of the teeth, or from local causes. The 
latter are frequent and come under the following heads: 1. Tardy 
eruption ; 2. Deflection due to the retention of temporary roots ; 3. 
Forward movement of the molars ; 4. Eotation from want of occlu- 
sion. 

1. Tardy eruption. — The natural order of eruption is : first bicus- 
pid ; second bicuspid ; cuspid. But this is disturbed occasionally so 
that the first bicuspid is followed by the cuspid, thus pushing it back- 
ward. When there is a lack of space the second bicuspid must seek 
its way between the first bicuspid and the first permanent molar, and 
if there is a lack of room it is crowded outside or within the arch. 
(Fig. 70.) 

2. Deflection.— When a temporary molar is retained too long, or 
its root is not absorbed as fast as the bicuspid is erupted, this obsta- 
cle may deflect the bicuspid or cause it to rotate more or less upon 



142 



IRREGULARITIES OF THE TEETH. 



its axis, being favored by the spongy character of the alveolar 
process. (Fig. 71.) 

3. The forward movement of the molars necessarily diminishes the 
space left for bicuspids and cuspids, and when the first bicuspid and 



Fig. 70. 




cuspid erupt before the second bicuspid, this may be crowded out of 
its proper place. 

4. A rotation of a bicuspid from a want of proper occlusion is not 
rare. An examination of the grinding surface of the bicuspid shows 
that it is designed to articulate with an opposing tooth. When its 

Fig. 71. 




two cusps fail to find an opposing cusp to keep them in place its 
function is lost and its fixedness of position endangered. 



I^OCAL CAUSES. 143 

Frequently more than one of these causes are at work, or one im- 
plies another. Thus if there is accord between the size of the jaw 
and that of the teeth, some of the local causes cannot arise, the cus- 
pid may erupt before the second bicuspid without disarranging the 
arch, and a bicuspid may be deflected by a deciduous root and ulti- 
mately move into place unless crowded upon by a six-year molar. 
Rotation may be the result of a crowded condition, throwing the 
tooth out of the arch when proper occlusion is out of the question. 

As the first bicuspid erupts before the second, it has all the advan- 
tage of such space as there is. It may be crowded out of place by 
the forward movement of the six-year molar together with the pre- 
mature eruption of the cuspid. Permanent deflection due to the re- 
tention of a deciduous root is out of the question when there is suf- 
ficient space, but rotation upon its axis from want of proper occlu- 
sion may occur here as elsewhere. 

The posterior surface of the bicuspid touches the first cuspid only 
at one point, being an angle and not a surface, and this is a fruitful 
source of irregularity. 

Irregularities of the Teeth Produced by the Extraction of the 
First Permanent Molar. 

Irregularities first attracted attention by the deformity they 
produced, not by their interference with function. Overcrowded 
anterior portions of the arch and displacement of individual teeth 
were noticed. A long time elapsed before the results of injudicious 
extraction were observed. Therefore, the first permanent molar was 
ruthlessly destroyed until comparatively recent times, producing a 
large proportion of irregularities in the form of malocclusion. This 
loss of function is produced so gradually that the patient is not 
aware of it ; he may notice inconvenience in mastication, but does 
not attribute it to the cause, as even persons of great intelligence 
know little about the occlusion of their teeth. 

This tooth has been hitherto sacrified for two reasons : — 

1st. Its early decay, brought about by the tax upon the system of 
the growing child and the neglect from which the teeth sufier, par- 
ticularly during the period of' its development. The parent usually 
does not know of its existence until the child complains of tooth- 
ache. 

2d. The tooth has been extracted to correct an overcrowded arch. 



144 IRREGULARITIKS OF THE TEETH. 

\yhen removed to stop pain, the pain is indeed relieved by ex- 
traction, but has in its train many evils hereafter pointed out. 
When removed to correct a crowded arch, twice as much space is 
gained as desirable, and the crowded arch is not relieved, as the 
cuspid, because of the length and strength of its root, remains sta- 
tionary, while the bicuspids move back singly or in pairs, leaving 
the position of the incisors unchanged. The disastrous effects of 
extracting the first molar become apparent when its function is 
understood. We cannot do better than give its fourfold function as 
stated by Dr. J. E. Cravens, of Indianapolis, in the annual of Uni- 
versal Medical Science of 1888 : 

"The permanent first molar has four distinct functions : (1) To 
supply additional surface for mastication when development has 
progressed so that the deciduous molars, unaided, are no longer 
competent to meet the requirements of nature. (2) To support the 
crowns of the deciduous molars when they have become unstable, 
because of absorption of their roots to accommodate the advance of 
their immediate successors, the bicuspids, which are usually erupted 
between the ninth and the eleventh years. The deciduous molars 
begin to loosen six to tw^elve months before their final displacement. 
Should a permanent first molar be extracted early — say between the 
seventh and the eighth years — the deciduous molars supported by it 
would loosen prematurely so as to be unserviceable for mastication, 
and perhaps be lost six to twelve months before the eruption of the 
succeeding bicuspids. (3) To guide the second bicuspid into posi- 
tion in event of a loss of this molar previous to eruption of the 
second bicuspid, the latter is liable to erupt back of its true position 
or after erupting nominally to float backward along the ridge of the 
gum, inclining posteriorly, in such a manner as seriously to impair 
its effectiveness as a masticating organ. This is particularly the 
case in the inferior maxilla. (4) To induce additional development 
of the horizontal portion of the lower jaw, immediately anterior to 
the ramus, in order to make easier the eruption of the permanent 
second molar, and to prevent the well-known tendency of the latter 
to tip forward, thus Aveakening the support of its roots and impair- 
ing its value as a grinder. 

" The permanent first molar is supposed by many observers to ex- 
ercise an important influence in establishing a proper angle to the 
inferior maxilla. If such idea is correct (and several conditions 



1 



I.OCAI. CAUSES. 145 

indicate that it is), it adds possibly another to the already long and 
important list of the functions pertaining to this tooth." 

The wholesale extraction of the first permanent molar in the 
past has, no doubt, caused arrest of development of the alveolar 
process as well as of the maxillary bones, for the process and jaws 
depend for their development largely on the function of the teeth, 
their articulation and their motion stimulating nutrition and en- 
larging the arch. 

Some of the older dentists, whose skill is the result of routine 
rather than knowledge, are still to be found extracting four sound 
molars without the least thought of the consequences. Such a one 
who was practicing in a southern parish not many years ago was 
in the habit of taking out the first permanent molar in every instance. 
He said the result was " that all the people in that part of the coun- 
try possessed good regular teeth, and that an irregularity was the 
exception." The author has observed in many cases the want of 
development of the alveolar process and sometimes the jaws from 
the extraction of those teeth. This assertion is verified in those 
cases where the germ has not developed and the tooth is missing. 
More marked instances are those where three or four germs are 
wanting. The loss of a tooth performing such a work as the first 
permanent molar impairs mastication, and produces vicious occlu- 
sion and is detrimental to the contour of the face. When extracted 
before the second molar is erupted, one-half or more of the grinding 
surface of the teeth is lost. 

The nutrition of the patient suffers in proportion, and health may 
be seriously impaired because of inability to masticate food properly. 

The horizontal portion of the lower jaw will be but imperfectly 
developed, because function, one of the most important means of 
development, is lost and insufficient room is left for the second and 
third molars. 

When a jaw with deciduous teeth is compared with one having 
permanent teeth, we notice a difference in the length of the rami 
and bodies, and a still greater difference in the angles. This differ- 
ence results from the gradual separation near the angle and is due to 
the growth of the molars. The arches of the permanent set are 
separated posteriorly by the eruption of the first permanent molnr. 
When these molars are lost before the second molars are in place, 
the characteristic angle of the jaw becomes less marked. The loss 
10 



146 IRREGULARITIES OF THE TEETH. 

of this molar on one side only will produce asymmetry of the two 
sides of the face, noticeable perhaps only to the trained eye, the 
parallelism of the two arches having been disturbed. K the two 
are lost early, the jaws approach each other more than normal near 
the angle, throwing the force of mastication forward. As the first 
and second bicuspids do not erupt until the tenth or eleventh year, 
and the deciduous molars loosen six to twelve months before they are 
displaced, the child is forced to masticate its food for several years 
on a portion of the arch designed for other purposes, compelling 
these teeth to perform the unnatural function of grinding. This 
confiision of functions produces but imperfect results and changes 
the outline of the face. 

As the. first permanent molar erupts it acts as a fixed point, sepa- 
rating and holding the jaws somewhat throughout their entire extent 
in front as well, so as to make room for the growing incisors. The 
deciduous incisors, being very much shorter than the permanent 
ones, necessarily have a shorter bite. When the first permanent 
molar is lost the natural bite is shortened, for this molar acts as a 
force which lengthens the arches backward and also separates them 
vertically. 

When this tooth is lost the lower permanent incisors as they de- 
velop strike with greater force against the upper and are carried 
forward. The change at first is imperceptible, but in the course of 
time these teeth will be found spreading more or less like a fan. 
Though the organic relation of the upper and lower jaw is not so ap- 
parent at first as that of other organs, and the two jaws seem to enjoy 
greater independence, proper occlusion is indispensable to their health, 
and the teeth in the lower arch are forced out of their sockets by 
a deposit of osseous material not consumed through proper function. 

Naturally bicuspids tend to move forward because of the inclination 
of the root and the angle formed by the two jaws, which makes 
the teeth strike at an angle as well. This tendency usually prevents 
them from moving back, even if the first molar is extracted. When 
the cusps are long they usually retain their natural articulation, but 
sometimes, as has been pointed out, they move backward. They 
may move back separately or may drop back together. (Fig. 72.) 
This dropping back destroys the articulation, causing the opposing 
teeth to strike only at certain points instead of bringing surfaces in 
contact, and frequently partial rotation upon their axes results. 



I.OCAL CAUSES. 



147 



The most ordinary result of the extraction of this tooth is the 
forward movement of the second and third molars (Fig. 73), caus- 




ing these to tip forward and resulting in vicious articulation, as 
shown by Dr. Davenport in the Dental Cosmos of July, 1887. Ex- 
ternally the articulation may appear not to have suffered, but when 



Fig. 73. 




it is examined inside of the arch, it is found that the opposing teeth 
meet only at certain points, becoming thereby partially useless. Fig. 
74 shows the forward movement of the first permanent molar. The 
temporary molars on right side are in place, thus holding the first per- 
manent molar in place, while on the left side the temporary molars 
have been extracted and the first molar has moved forward one- 
fourth inch. The force of mastication and the direction of the 
roots together with the eruption of the second molar increases this 
tendency. 



148 IRRKGULARITIES OF THE TEETH. 

Length of the rami, body, depth of sulci of the masticating sur- 
face and local peculiarities of the teeth in front may so modify the 

Fig 74. 



occlusion as to result in bilateral asymmetry, and the degree of tip- 
ping forward may be quite unlike. 

LocAii Irregularities of the Lower Jaw. 

The upper and the lower jaw are quite distinct in character, 
function and course of development, however similar they may 
appear to be. 

The upper when normal describes a portion of a larger circle, the 
teeth overlapping those of the lower. It is fixed, and depends for 
its function entirely on the activity of the lower. Owing to this 
immobility, when irregularities exist they are of a more marked 
constitutional type. Thus we have the various abnormal arches not 
seen in the lower ; the high and narrow vault and the inward 
curvature of alveolar processes. It has a greater sweep of 
development, and consequently greater possibility of irregularity in 
its anterior columns, because these are unrestricted, while the lower 
is restrained by the overlapping of the upper teeth. The lower jaw 
is hung loosely, but firmly, by its condyles, permitting motion in 
three directions, — antero-posterior, vertical and lateral. 

In Fig. 75 the six anterior inferior incisors are shown. Observe 
that the points of contact are at their cutting edges, the mesial and 
distal surfaces being rounded, which enables them to crowd easily 
past each other when force is applied ; the roots are flattened at their 
sides, so that when pressure is brought to bear upon them they move 



LOCAL CAUSES. 149 

with readiness over a considerable distance. That the pressure 
cannot well be exerted in a straight line through the posterior col- 
umn, and from thence extend in a curve through the anterior teeth, 
appears from the law of simple forces, which act in straight lines 
only. The cuspid, finding no resistance in front, but being resisted 
by the incisors slightly at the side, must necessarily pass forward. 
The lateral is too weak to afford resistance. Even if the centrals 
could be acted upon by the pressure from behind, they could be 
prevented from assuming a V-shape by the overlapping incisors 



Fig. 75. 




above ; for the more the upper arch is compressed laterally, and the 
mesial angle of the central is turned outward, the more will the 
distal angle be turned inward, and thus confine the lower incisors. 

The lower incisors being narrower than the upper only favors this 
tendency. These conditions are necessarily modified by the local 
peculiarities of the upper arch, the relative strength of the teeth and 
the nature of the occlusion being all-important factors in determin- 
ing final results. 

Fig. 76 is a diagram of a normal lower maxilla. The line a b 
passes through the cuspids, bicuspids and molars, and shows the 
direction of the force exerted by the posterior column upon the 
anterior. For its growth it depends far more upon function than 
the upper. The growth of the lower jaAV is limited to the posterior 
column, as has been mentioned, this being accomplished by the ab- 
sorption of the anterior border of the rami, while bone-cells are de- 
posited along its posterior border. Its freedom of motion is, however, 
retarded by the arch of the upper maxilla, for which reason irregu- 
larities are much rarer in the lower than the upper jaw as the 



150 



IRREGULARITIES OF THE TEETH. 



overlapping of the upper teeth tends to correct any predisposition to 
mal-arrangement. 

Irregularities of this jaw result more from local causes than those 
of the upper maxilla, except those found in the underhung jaw. Its 
development depends largely on mastication. Owing to its move- 
ments there are fewer irregularities in this maxilla and the jaw is 
more apt to be normal. Irregularities back of the cuspid are very 
rare. Occasional contractions of the lower arch occur, such as dip- 
ping in, which is due to peculiarities of occlusion. When cases of 
irregularity exist they are generally found in mouths the lower arch 
of which exceeds the upper in diameter, thus permitting less firm 
interlocking and greater freedom of individual teeth. 



Fig. 76. 



Fig. 77. 





When the diameter of the circle of the teeth of the lower jaw 
exceeds that of the upper, its lateral movement causes an enlarge- 
ment of the upper circle by opening the median suture, this condi- 
tion being indicated by the spreading of the superior central in- 
cisors. As has been shown in the chapter on migration of teeth, 
twisted bicuspids often result from entire want of occlusion or the 
touching of two opposing teeth at only one point. The most fre- 
quent form of irregularity is a crowding of the incisors. This is 
generally the case where the size of the teeth and the jaw are not in 
harmony, and is due to two causes : 1st. The teeth of the lower jaw 
are forced inward by occlusion, the diameter of the circle of the 
upper teeth being usually the smaller ; 2d. The forward movement 
of the posterior column. 

The two halves of the lower arch, like those of the upper, for 
obvious reasons do not present the same forms of irregularity. Like 
the upper jaw, the lower is subject to forward movement of the 



LOCAL CAUSES. 



151 



posterior column. A want of harmony in the development of upper 
and lower maxillae produces a crowded condition of the lower arch, 
resulting in pressure upon the anterior column. 

The direction of the roots of the lower molars greatly increases 
this tendency. When the crowns of the second and third molars 
are erupted the first molar is pushed forward. The pressure is ex- 
erted principally through the posterior column upon the cuspid and 
is in a straight line. This tooth, by virtue of its rounded cusp, slips 
by the lateral and is projected forward often beyond the central 
incisors, leaving the lateral behind. 

Like the upper maxillse the two halves of the alveolar arch are 
separate, and are modified independently. An irregularity on one 
side by no means indicates a similar irregularity on the other, owing 
to the difference of pressure that may be exerted. 

Fig. 77 shows the left dental arch normal, but the forward move- 
ment of the posterior column has caused the right lateral to fall 



Fig. 78. 





behind. As the two columns converge anteriorly they exert their 
pressure in this direction, in consequence of which we find irregu- 
larities of the lower jaw confined for the most part to the region of 
the incisors. 

Though, as stated before, the laterals are generally pressed within 
while the centrals occupy their usual position, these teeth may stand 
at various angles which are determined by the local peculiarities of 
the teeth of the upper maxilla. Thus it may happen that a cuspid 
or a lateral may strike outside of its antagonist of the opposite 
jaw. 

Fig. 78 illustrates a common form of irregularity in which both 
posterior columns have moved forward. The laterals are crowded 
backwards and inwards. The lines of force are also directed in- 



152 



IRREGULARITIES OF THE TEETH. 



ward, but a V-shaped arch is prevented by the lower centrals 
striking against the palatal surfaces of the upper centrals. If the 
cause of this form of irregularity is borne in mind it will be under- 
stood why the extraction of a lower lateral or central makes this 






Tig. 




form of irregularity still worse, inasmuch as it disarranges the occlu- 
sion of the cuspids. 

In Fig. 79 we see the right dental arch normal. The left pos- 
terior column has pushed against the lateral, and meeting with 



Fig 81 




sufficient resistance, the central is carried backward. While erupt- 
ing, the central was carried inward, owning to a w^ant of harmony of 



development. Two centrals have been 
though this form of irregularity is rare. 



found directed inward, 



LOCAI. CAUSES. 



153 



Fig. 80 shows the left dental arch normal. The forward move- 
ment of the posterior column on the right side has caused the cuspid 
to advance beyond the line of the incisors. The rotation of the 
cuspid upon its axis caused it to pass by the lateral, leaving it in 
position. This is a common form of irregularity. Occasionally the 
cuspid is carried forward in the direction of the pressure. Such a 
case is illustrated in Fig. 81. The left lateral has been carried 
inward in the manner already described. The posterior column has 
pushed the cuspid on the right side laterally so that it occupies the 
position of the right lateral and the bicuspid is carried forward 
and outside of the arch. 



The Inferior Cuspid. 

The cuspid erupts in line with the other anterior teeth unlike the 
upper, the crypt of which is above and outside of the lateral incisor 
and bicuspids. For this reason and the fact that the upper cuspid 
tends to keep it in position by ^^^ 32 

occlusion, irregularities of the 
cuspid of the lower jaw are 
not so common as those of the 
upper. When the tooth is 
found out of line, it is anterior 
of its normal position, — rarely, 
if ever, posterior. Its eruption may be tardy, giving the advantage 
of time to the upper cuspid and directing the lower cuspid outward. 
In a crowded jaw a disarrangement of the incisors may follow, leav- 

FiG. 83. 





ing the lateral almost directly behind the cuspid, as in Fig. 81. When 
there is a malposition of the cuspid on one side of the maxilla, the 
cuspid of the opposite is usually pushed forward, as seen in the 
Same illustration. 



154 



IRREGULARITIES OF THE TEETH. 



Owing to a malposition of the germ, the cuspid may be found 
outside of the incisors in the median line (Fig. 82), or even inside 
of the arch (Fig. 83). Rarely it is found on the median line be- 
tween the incisors as shown in this illustration. 



Lower Bicuspids. 

Like the cuspid, the position of the bicuspid is most frequently 
affected by the forward movement of the posterior columns. An 
irregularity in a lateral direction is rare, since the density of the 
lower maxilla is unfavorable to this. 

Whenever a bicuspid is found without or within the arch, it is 
due to the undue retention of the temporary teeth. Fig. 84 shows 
the second bicuspid situated inside the arch, while Fig. 85 shows the 
first bicuspid inside and the second bicuspid outside of the arch. 
Twisted bicuspids occur frequently from a want of proper occlusion, 
when the space yielded by the lower jaw is larger than that of the 
upper, or when the first molar is extracted. 



Fig. 84. 



Fig. 85. 




When the second temporary molar is retained too long, the first 
permanent molar may be pushed forward, thus confining the bicus- 
pid and preventing it from erupting. 



CHAPTER X. 
ANTEEIOE PROTKUSIONS. 

MIGRATION OF TEETH. 

That teeth move when acted upon by some external force is 
known to every practitioner, and is utilized in his operations by 
producing temporary separations, in regulating and the like. Why 
they should move from their normal position without any apparent 
cause is not so easy to explain, and theories have been recently 
advanced to account for this. It is obvious that when the arch of 
the alveolar process is greater than that of the combined diameters 
of the teeth, there must be a space or spaces somewhere. This space 
is usually equally distributed among the anterior teeth. Sometimes, 
however, spaces are found that disfigure the mouth, and besides 
these we find occasionally one or more teeth that appear to have 
rotated upon their axes. An inquiry into these forms of motion is 
the province of this chapter. 

This subject is best considered under two heads. 

A. Perfect occlusion. 

B. Proper relation between waste and repair. 

A. If the occlusion of the teeth is perfect, so that each tooth is 
kept in place by its adjoining neighbors and the opposing tooth, 
dislodgment is impossible. All teeth should touch those adjoining 
them at the extremities of their greatest diameter. This allows a 
slight lateral motion. 

Good occlusion differs according to the function of different teeth. 
Their shapes indicate this. The upper and lower incisors overlap 
each other, producing what is termed the overbite. In the normal 
relation they strike in a straight line which passes through their 
roots. The curved lingual surface of the upper incisors allows for 
their sliding into this position. The force being thus exerted in 
straight lines, there is a constant tendency to keep them in position, 

155 



156 IRREGULARITIES OF THE TEETH. 

and as the pressure upward and downward is vertical, spreading of 
the upper incisors is impossible. The relation of cuspids is similar. 
Quite othenvise with bicuspids and molars. Beginning with the bi- 
cuspids, we find the cusps of the first superior bicuspid striking not 
over that of the first lower bicuspid alone, but over the angles 
formed by the distal side of the first lower and mesial side of the 
second. Each tooth beginning at this point is not only in relation 
to one below, but to two, and when one of these teeth is extracted 
the order of the mouth is disturbed and a rearrangement of some 
kind usually follows. What this will be depends on a variety of 
circumstances. 

A t}^ical example is furnished by the extraction of the first molar. 
Every practitioner has observed the forward movement of the second 
molar as a consequence. A tilting forward of this tooth results. 
The reason for this is obvious when we remember that the posterior 
cusp of the first upper molar strikes the anterior cusp of the second 
lower and exerts its whole force, which was meant to be distributed 
on both cusps, on it. 

B. The position of the teeth is not determined alone by the rela- 
tive size of the maxillae and the occlusion of the teeth. Nutrition 
and absorption, waste and repair, play an important part. On the 
perfect harmony of these the beauty and health of the teeth depend. 
Changes in the position and removal of bone-cells go on constantly 
and vary with the age and other physical conditions of the patient. 
This disposition and removal of bone-3ells is seen in the changes 
that the lower maxillae undergo during difierent periods of life. 
When the deciduous teeth are replaced by the permanent ones, the 
arch of the jaw becomes more pronounced, and there is a lengthen- 
ing of the alveolar ridge backward to accommodate the molars. When 
the senile changes take place the angle of the jaw becomes 
more obtuse. That there is a similar adjustment to circumstances 
going on constantly is proven by circumstances. Correction of irreg- 
ularities depends on this. The position of the teeth in the alveoli 
is determined solely by the tissues around it. By producing a pres- 
sure in a given direction, bone-cells may be removed on one side and 
others deposited on the other and the position of the tooth changed. 
The change in the deposit and removal of osseous matter is not un- 
like that of the deposit of particles of earth in the bed of a river 
where stakes have been placed for the purpose of locating the bed of 



ANTERIOR PROTRUSIONS. 157 

the river. By the successive deposit and removal of these particles 
the position of these may be changed and even the current of the 
river. This illustration may help to make clear changes in the 
contour and density of the alveolar processes depending on the 
changes of blood-supply and absorption. Irritation may thus stim- 
ulate the activity of the capillaries to a more than ordinary degree 
of repair. 

Every tooth exerts a pressure of its own in different directions. 
Were this not so it would be difficult to account for the elongation 
of a tooth when its opponent is extracted. This pressure is healthy 
and implies the antagonism of opposing teeth. If this occlusion is 
wanting, the relation of waste and repair is disturbed. An excess 
of bone-cells is often deposited as a result. 

When these two fundamental laws of good occlusion and balanced 
waste and repair are violated one of the three following conditions 
may follow : 

(1), The movement of individual teeth in straight lines. 

(2), The rotation of individual teeth upon their axes. 

(3), The forward movement of groups of teeth and the alveolar 
processes supporting them. 

The Movement of Individual Teeth in Straight Lines. 

It was stated above that when the alveolar processes and teeth 
correspond in size and the occlusion is good that spaces between the 
teeth are out of the question. Sometimes a space is found between 
the central incisors. If the occlusion is good otherwise, this space is 
due to a continuance of growth at the margin of the suture, i. e., 
there is a greater deposit of osseous material than is needed, pro- 
ducing a larger diameter the jaw than the teeth. This begins 
usually at an early period in life and continues till the growth of the 
osseous system has ceased. As the jaw develops in the child while 
the temporary teeth remain, it is but natural that spaces should be 
formed in time until the permanent teeth take their place. 

Spaces may be artifically created in time by forcible separation by 
means of wedges. In former years, when more force was applied 
by dentists, irritation was created, and absorption on one side induced. 
In this way several teeth were sometimes crow^ded in one direction. 
When the anterior incisors do not strike on a line, but at an angle, 



158 IRREGULARITIES OF THE TEETH. 

so that the cutting-edges of the lower incisors strike against the 
inclined plane of the lingual surface of the upper incisors, an out- 
ward pressure is exerted and the incisors separate. The spaces that 
are so frequently seen in the permanent incisors in children are in 
many cases produced by the tardy eruption of the cuspids. When 
the cuspids come down into place these spaces disappear. Spaces 
are rarely if ever observed between molars. 

Again, the lower jaw, if too large for the upper jaw, may act as a 
wedge, and by striking against it may spread the central suture. 
The spaces between these teeth are usually found to be healthy. It 
is not reasonable to suppose that either salivary or germinal calculus 
or inflamed gums could produce this motion. Were the pressure 
exerted on one side only there might appear to be some ground for 
this supposition, providing calculus exerted a pressure too great for 
the rest of the teeth to resist. But when calculus is deposited on 
both sides the pressure exerted would be counterbalanced and 
lateral motion could not take place. Those who hold this opinion 
are probably misled by the fact that a tooth may be dislodged by 
calculus from its socket vertically. But this is in accordance with 
mechanical principles. In this case the calculus diminishes the 
diameter of the socket and the wedge-shaped root is forced out. 

EoTATiox OF Individual Teeth upon their Axes. 

When a tooth touches its opposites only at one point or the oppos- 
ing tooth was extracted, as it frequently happens with bicuspids, 
instead of articulating with surfaces, rotation may result. In this 
case bone-cells are deposited on one side, while those at an angle 
with these are removed. This produces a slight rotation which 
twists the tooth. That this process is physiological, is proven by the 
healthy state of the gums and alveolus which is found in most of 
these cases. Fig. 86 not only shows the rotary motion to the bicuspids, 
but also spontaneous motion in direct lines — a condition frequently 
observed by the author. 

The Forward Movement of Groups of Teeth and the 
Alveolar Process Supporting Them. 

In young persons, when the blood supply is rich with nutritious 
material, and when waste and repair go on rapidly, the four 



ANTERIOR PROTRUSIONS. 



159 



and sometimes six anterior teeth and alveolar processes are carried 
forward. This pro- 
per occlusion with 
the inferior incisors 
becomes impossible, 
and these become 
elongated and, fail- 
ing to find a support 
in the upper incisors, 
strike against the 
roof of the mouth. 
Irritation is pro- 
duced and an ex- 
cessive flow of blood 
to the parts follows. 




Thus we have : — 



Anterior Protrusions from Constitutional and Local Causes. 

One of the most interesting forms of irregularity is that in which 
the inferior incisors impinge upon the mucous membrane of the roof 
of the mouth and the superior centrals, laterals, cuspids and bicus- 
pids, having moved forward, project to such an extent that the upper 
lip cannot close over them. It should be observed : 

1. That these cases are not confined to normal individuals, but are 
found among idiots, deaf and dumb, blind, demented and insane. 

2. The deformity is not seen in temporary teeth, but is confined to 
the permanent set, beginning at the seventh or eighth year and in- 
creasing with age. When not corrected the teeth will finally pro- 
ject at an obtuse angle, as is illustrated by a case of a woman 
fifty-five or sixty years of age that came to our notice, whose teeth 
projected almost horizontally. 

3. The vault connected with this irregularity is usually low, 
though sometimes high, in which case it is more pronounced ; just 
as V and saddle-shaped arches are more pronounced w^heii associ- 
ated with a high vault. 

4. The irregularity begins at the central incisors, extending back- 
ward. 

5. Generally later in life tartar collects around the roots, and 
Riggs' disease sets in, exaggerating the condition. 

6. In the majority of cases the superior maxilla is arrested, and 



160 IRREGULARITIES OF THE TEETH. 

the teeth project at an angle of 20°, carrying the alveolar process 
with them, in order that they may strike over the lower incisors. 

Dr. Kingsley who first described this form of irregularity, is right 
in his statement that this condition is neither inherited nor the re- 
sult of thumb-sucking. The conditions under which this irregularity 
is brought about are both constitutional and local. It should be 
noticed that the excessive proliferation of bone-cells does not begin 
before the sixth or seventh year, hence not until the permanent teeth 
are erupted. A want of balance of nervous function, resulting from 
neurotic conditions or a transmitted tendency to disease, may inter- 
fere with the centres of ossification, which interference, as has been 
shown, frequently finds expression in the anterior part of the mouth 
sometimes producing a high vault, contracted arches, or excessive or 
deficient deposition of bone-cells. An excessive proliferation of 
bone-cells near the median line of the superior alveolar process tilts 
the axes of the erupting centrals slightly outward. This direction 
once being given to them, when the lower incisors strike against 
them they do not find the resistance of correct occlusion, but act 
upon them as upon an inclined plane, throwing them out more and 
more during the process of eruption. This must necessarily terminate 
in striking the process itself, increased activity of nutrition which irri- 
tation sets up, resulting in excessive development. The tilting forward 
of the upper incisors increases the distance between them, and the 
lower incisors do not find the resistance belondno- to natural func- 
tion. The consequence is the elongation of the lower anterior alveo- 
lar arch, a circumstance to be noted in these cases. The eruption of 
the first permanent molars determines the relation of the jaws to each 
other ; occasionally they do not develop their full length. In either 
case the lower incisors strike against the mucous membrane of the 



Fig. 8T. 




roof cf the mouth, which constant irritation stimulates the deposition 



ANTERIOR PROTRUSIONS. 



161 




of bone-cells in the process, as if nature would defend it against the 
abnormal pressure of the lower teeth. Were the occlusion correct, 
the constant pressure on the roots of the teeth would doubtless, in 
part, counterbalance the excessive deposit by waste. As it is, the 
roots of the upper inci- 
sors form an angle with 
the cutting-edge of the 
lower teeth, and as the 
mouth opens and closes, 
the force of the lower 
incisors is not only spent 
on the superior process, 
but also through it on 
the roots of the upper 
teeth, forcing them out 

more and more. Fig. 87 shows the starting-point. The central 
incisors have just commenced to move forward. The model is from 
the mouth of a girl eleven years of age. The trouble is extended to 
the neighboring teeth from the nature of the occlusion. Fig. 88 
shows the incisors and alveolar process carried forward by the 
excessive deposition 
of bone-cells. By the 
action of the lower 
lip, which cannot 
close over the cutting- 
edges of the upper 
teeth, but soon gets 
between the superior 
and inferior incisors, 
the former are press- 
ed out still more. Fig. 
89 shows a side view 
of this form of irregu- 
larities. Fig. 89-A 
illustrates a remark- 
able case of migration of the molars. 

Want of function encourages a deposit of tartar around the roots of 
the teeth, inducing Riggs' disease later in life and loosening the teeth. 
11 




CHAPTER XI. 
SUPERNUMERAEY TEETH. 

SuPEENUMEEARY teeth are a freak of nature, for wliicli no cause 
has, as yet, been assigned. It may, of course, be stated that addi- 
tional germs were formed during foetal life, but this is no true ex- 
planation, for the question still arises, " What caused these ? " 

Plants put forth adventitious buds and show monstrosities in all 
their organs; animals are not always developed according to the 
law of their species ; the human race shows monstrosities in every 
organ. It is therefore not to be wondered at that we see additional 
teeth. They were noticed by the earliest writers on dentistry, even 
before Christ. There is no doubt that what the public calls a double 
row of teeth is often merely malposition of the regular member, and 
that many a supernumerary tooth, when well formed, escapes notice. 
It is best, before making a statement in doubtful cases as to the 
class to which the supernumerary tooth belongs to take an impres- 
sion ; then it can be studied and compared wdth the rest at leisure. 

Deviation from the normal number is more marked in the per- 
manent than the temporary set. Little mention has been made of 
deviations in number in the deciduous set, because more rare and 
because the deciduous teeth have less individuality than the perma- 
nent ones, which would cause an additional tooth to escape notice. 
The author has come across four cases in his practice of supernum- 
erary laterals in deciduous teeth. Three of these cases presented a 
supplemental lateral on the right side (Fig. 90) ; the fourth had them 
on both sides. It is interesting to notice that the excess was found 
mostly on the right side, for the reason that greater development of 
organs on the right side, including the jaw, have hitherto been 
ascribed to more frequent use. As the germs of the temporary 
teeth are formed before birth, this theory cannot stand in this in- 
stance at least. 

When we come to the permanent teeth we find a distinction 
between cases presenting merely a variation in number and those 
162 



SUPERNUMERARY TEETH. 



163 



showing malformed supernumerary teeth. These may be considered 
under the heads of supplemental teeth and monstrosities. The 
former are like normal teeth, and it is difficult to distinguish them 
from these. The contour of the latter, like that of all monstrosities, 
is governed apparently by no law, excepting a want of definiteness. 



Fig 




However, the root is conical and the crown may be lobed or have 
the appearance of having been partially folded or poorly formed. 

Adventitious teeth are more frequently found in the upper jaw 
than in the lower. It is a rare thing to find a well-formed super- 
numerary central incisor. The author has a cast showing five 
equally well-formed incisors in the lower jaw. Whether the super- 
numerary tooth is a central or lateral cannot be determined by the 
form. Coleman records a case having four well-formed central in- 
cisors in the upper jaw. Partially developed additional incisors are 



Fig. 91. 




Illp?^"; n 



not rare. These teeth are found at different angles. They are seen 
erupting behind the arch, in front of it, or between two otlier teeth. 
Fig. 91 shows a conical tooth between two ill-shaped centrals, one 



164 



IRREGULARITIES OF THE TEETH. 



of which stands almost at right angles with the arch. Another case 
still more interesting (Fig. 92) has two central monstrosities separat- 
ing the legitimate centrals. Fig. 93 shows two supernumerary cen- 



FiQ. 93. 



Fig. 94. 




trals having the appearance of being convoluted, between the usual 
centrals. In Fig. 94 we see two supernumerary central teeth between 
the laterals, all of which are placed inside the regular arch. 

Laterals in excess are not so common as centrals. These are 
usually more like the normal teeth. Sometimes they are found on 

Fig. 95. Fig. 




both sides. Fig. 95 shows a lateral behind the arch and between 
the central and the lateral. In the lower jaw they are rare. 

In Fig. 96 one of the supernumerary laterals is placed back of the 

Fig. 97. Fig. 98. 




right cuspid and at right angles with it. The author has two 
models similar to this in his collection. Cuspids, bicuspids and 
molars are not often found in excess. 



SUPERNUMERARY TEETH. 



165 



Fig. 97 shows a supernumerary cuspid, twisted upon its axis on 
the right side of inferior maxilla. The right lateral is missing and 
the cuspid is, no doubt, a malformed lateral, although it has the ap- 



FlG. 




pearance of a perfect cuspid. In Fig. 98 we see a dental anomaly 
to which attention is directed by Dr. Rickey, of San Francisco. In 
this case it is difficult to say which is the supernumerary tooth. Fig. 
99 shows four well-formed molars in each side. 




Fig. 100 illustrates a very rare case of supernumerary teeth, eight 
in all. They do not seem to be confined to any one class, incisors, 
cuspids and bicuspids seem to be duplicated. This cut certainly il- 
lustrates a double set of teeth. The model is in the Pennsylvania 
College of Dental Surgery. 



CHAPTER XII. 

THUMB AND FINGER-SUCKIXG AS A CAUSE OFIKREGULA.EITY. 

Ix tlie chapter on refutation of old theories regarding the etiology 
of irregularities of the jaws and teeth, the author has stated his rea- 
sons why the high vault and the V and saddle-shaped arches can- 
not be ascribed indiscriminately to thumb-sucking, as has been the 
custom. 

Hitherto the greatest confusion of ideas has been current among 
practitioners as to the etiological differentiation of these cases. It 
behooves the author to describe the conditions that are due to 
thumb-sucking in such a way that the student may be aided in 
making a diagnosis. In cases of irregularities due to thumb-sucking 
we find several teeth and the alveolar j^rocess brought forward. 
Frequently spaces are found between them, so that they stand out 
more and more fan-shaped. The vault may be high, but is usually 
low like that seen in Fig. 103. The teeth are frequently affected 
only on one side, the shape and extent depending upon the direc- 
tion of the force and the hand employed in sucking. In the 
V-shaped arch the teeth are crowded and point toward the centre, 
owing to a force applied by the posterior column and spent on both 
halves toward the median line. The vault may or may not be 
arched. In the saddle-shaped arch the teeth are crowded, except 
in cases due to hypertrophy, and they stand perpendicular. The 
vault may be high or low. In cases of thumb-sucking, the teeth 
of the inferior maxilla do not articulate properly with the upper, 
and are often turned inward, which is caused by the pressure of the 
thumb upon the cutting-edges. We see from this that the distinguish- 
ing feature of a case of thumb-sucking is the spreading of all or a 
part of the anterior teeth, and that the lower teeth are usually 
turned inward. 

When the vault is high, it is quite marked in the anterior portion 
of the roof of the mouth ; but this is by no means a characteristic 
feature. As the habit of thumb-sucking usually terminates before 
166 



THUMB AND FINGER-SUCKING. 167 

the eruption of the permanent teeth, cases of irregularities resulting 
from thumb-sucking in children over ten years of age are rare. (It 
will be of interest to the student to note a number of cases that 
have come under the observation of the author.) 

Babies usually commence to suck their fingers within a few hours 
after birth, — in the majority of cases not later than the first week. 
The habit is therefore well fixed before the temporary teeth begin 
to erupt. This being the case, the teeth and the alveolar process 
are naturally afiected in their development if the pressure is contin- 
uous. The extent, shape and location of the irregularity depends 
upon the hand employed and the position of the thumb and finger 
used. The right or left side are affected according to the hand 
used, though occasionally we find it in the median line. 

As the child usually discontinues the habit before the time of the 
eruption of the permanent teeth, deformities produced by thumb- 
sucking are usually confined to the temporary set. 

Fig. 101 shows the forward movement of the right central and 
lateral incisor. The model was taken from an impression of the 
teeth of a little girl two and a half years of age. While in the act of 
sucking, the right arm rested upon the breast, and the ball of the 
thumb was directed against the pala- ^^^ ^^^ 

tine surfaces of the incisors, which 
were carried forward. The child dis- 
continued the habit at four. It will 
be observed that while the cutting- 
edges of the teeth have been slightly 
pressed forward, and a very slight 
impression has been made on the al- 
veolar process, none was made on the roots of the teeth, and conse- 
quently no deformity exists where the germs of the permanent teeth 
are located. After the child discontinued the habit, the teeth soon 
returned to their natural position, aided by the pressure from the 
lip. At this age the absorption and deposition of bone-cells is so 
active that very marked deformities are frequently corrected before 
the temporary teeth are lost, providing that the habit ceases in 
infancy. 

Fig. 102 shows quite a different deformity. Here we see the teeth 
fully developed, but a marked deformity existing at the median 
line. This case is that of a child six years of age. The thumb was 




168 



IRREGULARITIES OF THE TEETH. 



held in the mouth so that the teeth came in contact with the thumb 
at right angles, preventing the development of the alveolar process. 
The teeth of the inferior maxilla do not articulate properly with 



Fio. 102. 




those of the superior, which is caused by the thumb having rotated 
upon the lower teeth after the upper had closed upon them. The 
hard palate was flat and normal, showing that the pressure was 
direct upon the teeth, and that the thumb did not come in contact 




wath the tissues of the mouth. When the habit is continued during 
the development of the permanent set, the deformity is more marked 
because there is more leverage, as is shown in Fig. 103. This is a 
case in which the palate is flat and normal, showing that the pres- 



THUMB AND FINGER-SUCKING. 169 

sure was direct upon the teeth, and that the thumb did not come 
in contact with the tissues of the mouth. The superior jaw and 
teeth are brought forward by absorption and deposition of bone-cells, 
and the lower teeth and jaw are carried inward. 

These cases are so unlike those of any other form of irregularity 
of the permanent set that it would seem impossible to overlook the 
cause. The alveolar process and teeth assume the shape of the 
object or thing sucked. 

Fig. 104 shows the front view of a case of thumb-sucking. The 
teeth have developed their normal length ; but arrest of the devel- 
opment of the superior alveolar process has taken place similar to 

^. Fig. 104. 




After Wilson. 



Fig. 102. In Fig. 104 there has been quite a protrusion and forward 
movement of superior incisors and alveolar process, the teeth stand- 
ing fan-shaped. The lower incisors are pressed inward and crowded 
together. The space is greater on the right side than on the left, 



showing that the right hand was used. 



PAET II.-TEEATME^^T. 



CHAPTER I. 

PRELIMINARY CONSIDERATIONS. 

I. DIAGNOSIS. 

Frequently when a case of irregularity is presented we can tell 
by the general contour and profile of the face whether the case is 
one of the constitutional type, the external proportions being affected 
by a decided V-shaped arch, excessively developed alveoli or under- 
hung jaw. One of the first things a dentist has to learn is to observe 
carefully. In determining the correctness or incorrectness of the 
outline of the mouth and jaw he instinctively takes it in as a whole 
on the same principle that when we look at the picture of a friend 
we decide at once whether it is a good likeness or not, reserving our 
judgment of particular points until later. 

Observe each jaw. See whether it has a normal outline or whether 
it belongs to the V-shaped or saddle-shaped variety. Notice the 
vault. These are important points in deciding what appliances can 
be used. Examine the occlusion, letting the patient open and close 
his mouth slowly. No detail must go unnoticed. The beginner 
should familiarize himself with the individuality of each class of 
teeth, both as to outline and occlusion. For this purpose he is 
advised to study the very excellent article by Drs. E. T. Starr and 
F. L. Wise, in the August number of the Cosmos, Vol. XXXI. 

When there is an asymmetry of the upper and lower jaws, one 
being larger than the other, the occlusion from the cuspid back is 
usually wrong. In such cases it generally strikes in front of the 
lower cuspid, instead of between it and the bicuspid, disarranging 
the articulation of every tooth back of it. We cannot stop here to 
speak of the different forms of mal-occlusion ; the dentist who never 
ceases to be a student will see these for himself. 
170 



PRELIMINARY CONSIDERATIONS. 171 

The difficulty in local irregularities is usually detected with readi- 
ness, for it is either found in the alveolar arch or the mal-position of 
individual teeth. 

Before giving your opinion inquire into the family history. While 
I cannot agree with Kingsley that it is useless to try to correct an 
irregularity peculiar to a family type, nature reverting to her origi- 
nal design, notwithstanding long-continued efforts, yet it is often- 
times well to wait until the patient is of an age when it can be de- 
termined what permanent form the jaw will assume. Many cases 
can be modified and thus be made less unsightly, even if the difficul- 
ties cannot be wholly overcome. 

The first examination is supplemented by a study from the model 
which is considered later on. 

In making a prognosis the extent of the deformity must be taken 
into consideration. There are numerous cases that nature will cor- 
rect without interference on the part of the dentist. Thus cuspids 
and bicuspids quite frequently erupt out of position, but gradually 
find their proper place. 

Apparent deformities are common during second dentition, while 
some of the deciduous teeth are still in position ; the difference in 
size between the two sets of teeth and consequent mal-occlusion 
alarms persons who are not familiar with these deformities, while 
time will bring about harmony. 

One must exercise caution in making a statement as to the ease or 
difficulty of correction or the time required, as many a case that 
seems to present no difficulties will give much trouble, because the 
resistance cannot be determined. Time spent in a careful examina- 
tion of the case is well spent. Haste may produce embarrassing re- 
sults. Therefore every particular in the deformity must be studied, 
and the dentist must forecast in his mind the appliances that may be 
used, the different steps to be taken and the time required before he 
can make a prognosis with approximate correctness. 

II. AGE. 

On the average, however, it may be said approximately that the 
best time for interference in the majority of cases is from the twelflli 
to the fourteenth year. At this time — the transitional period between 
childhood and puberty — -all of the teeth are erupted, general nutrition 
is most active, the osseous system is in the constructive stage, and the 



172 IRREGULARITIES OF THE TEETH. 

formative process is in vigorous operation. At this time, also, the 
roots of the teeth are not fully developed, but are more or less loosely 
confined within the alveoli, and the apical foramina are large, thus 
lessening the liability of impairment of the blood supply and conse- 
quent destruction of the pulp. 

The conditions mentioned as existing at the twelfth to the four- 
teenth year, being coincident with the completion of the eruption of 
the teeth, it naturally follows that the reverse holds true ; hence, in 
any case in which the teeth are fully erupted we may proceed to 
operate, irrespective of the age of the patient. 

The probability of a perfectly satisfactory result in regulating de- 
creases yearly after the age of puberty, and after the age of twenty- 
six the chances of a really satisfactory result are very meagre ; for 
at this time the entire osseous system is fully developed, and there is 
little probability of extensive deposit of ossific material. It is possi- 
ble to regulate deformities, even as late as the thirtieth year, but the 
resulting pain is so severe, and the mechanical force necessary to 
produce absorption of the obstructive portions of the alveoli is so 
great, that the end hardly justifies the means. When regulated so 
late in life, retentive and corrective plates must be worn for years to 
hold the teeth in place until ossific material shall have formed to 
retain them in their new position. 

In some cases of late correction, absorption of the alveolar process 
not being followed by compensatory ossific deposit, the mechanical 
interference produces chronic inflammation of the peridental mem- 
brane, i. e., a veritable pyorrhoea alveolaris and excessive absorption 
of the gums and alveolar process had been produced. I observed 
this very condition in the mouth of a lady of thirty-five, in whom 
an extended and, I may add, ill-advised operation had been per- 
formed. If the teeth must be regulated at this period of life, the 
operation should be conducted with great caution, and the patient 
should be duly impressed with a doubtful prognosis. When the 
patient insists upon an attempt at regulation, and is willing to as- 
sume the responsibility of failure, we are perhaps justified in opera- 
ting in any case of reasonable age. 

It must be borne in mind that the physiological process of regu- 
lating teeth differs from the repair in cases of fractures of the 
osseous system, which, under favorable conditions, is possible up to 
advanced age. In the osseous system two parts of homogeneous 



PRELIMINARY CONSIDERATIONS. 173 

structure are united. Not so in the case of correcting an irregular, 
ity. Here the root of the teeth, a dense structure, is enclosed in the 
spongy structure of the alveolus. The nutrition in the alveoli is 
extremely active during first and second dentition until the roots 
are perfectly formed — that is, up to the twentieth year. After that, 
the blood supply being less, when the alveolus is injured, waste and 
repair do not go on so rapidly. Nutrition; is lowered, as is shown 
by the separation of teeth and recession of gums in some cases of 
rapid wedging, as well as in cases of pyorrhoea alveolaris. That the 
attachment of a tooth to the alveolus later in life cannot be com- 
pared to the union of a fractured bone is evident from the fact that 
teeth, where regulated, are apt to return to their original position 
unless kept in position by an appliance for a time, and aided by 
proper occlusion, because the new tissue is not as strong as the origi- 
nal tissue, while, on the other hand, the bones and cicatricial tissue 
are made of the same material. 

III. STATE OF HEALTH. 

Having considered in detail the proper period for regulating, we 
are confronted with another question of perhaps as great import- 
ance, viz., the general health and constitutional peculiarities of the 
patient. Inasmuch as the majority of cases for regulation are 
youthful, this matter of the general health is no slight consideration. 
It is an unfortunate fact that the most favorable period for opera- 
tion is one of the most critical in the life of the patient, so far as the 
general health is concerned. 

From the age of twelve to sixteen, the rapidly-growing boy or 
girl is subjected to many physical changes, entailing profound dis- 
turbances of the general and trophic nervous systems. Prolonged 
and injudicious hours of study, over-exertion, bad air, improper or 
insufficient food, sexual irritation, and many other disturbing ele- 
ments are apt to become prominent factors in the daily life of the 
patient. 

The matter of sexual disturbance is of especial importance in 
females, on account of the new function— menstruation — which as- 
serts itself at this period. When we superadd to these physiological 
perturbations and circumstances of environment, the perversion of 
nutrition consequent upon congenital weakness, rachitis, hereditary 
syphilis or the exanthemata, the important bearing of the condition 



174 IRREGULARITIES OF THE TEETH. 

of the general health upon our operative procedures is very mani- 
fest. We should defer operating, therefore, on young persons in 
dehcate health until such time as they have become improved by 
proper treatment ; and it behooves us as scientific dentists to know 
something of these general conditions, so that we may, in all con- 
scientiousness, place them in proper hands for constitutional treat- 
ment. 

Unfortunately, the patients that present themselves are mostly 
neurotic, as has been pointed out in Chapter X. on Etiology. This 
complicates the dangers arising from careless procedures. It is of 
the utmost importance that the assimilation of the patient should 
be normal. It is the dentist's duty to inquire into this. The pa- 
tient should eat sufficient plain, nutritious food that is not stimulating. 
In many cases it becomes difficult to do this, as the appliance may 
hinder mastication. He should have an abundance of sleep in a 
well-ventilated room and should be in the open air as much as pos- 
sible. The mind should be placid and agreeably occupied. There 
is nothing like this to aid him to forget the irritation during the 
process. Repression of pain is as great a tax on the nervous sys- 
tem as the pain itself. Parents and dentists should therefore not be 
satisfied with the fact that the patient says nothing. He should be 
encouraged to give expression to his feelings if he is of a reticent dis- 
position, for this is an aid in deciding the amount of time required 
for each step. 

To carry out the program it may be necessary to take the patient 
out of school or to diminish his tasks. School is a place where it is 
difficult to obtain fresh air ; exercise is almost impossible. Such a 
patient cannot be brought under the necessary discipline of the 
school-room without detriment to his health and spirits. School-life, 
in itself^ is a heavy tax during the period of development ; to add the 
strain of correcting an irregularity to his other cares is cruel. Girls 
should receive especial attention. Many of them are morbidly con- 
scientious and ambitious and unduly reserved. They sufier much 
and say little. They do not find the relief that boys do in play 
out of doors. The sights and sounds in field and woods, and even 
the street, that furnish diversion to the active boy, are denied the 
girl. Her life is more circumscribed, hence more subject to passive 
suffering. Great wisdom and judgment are requii-ed in such cases. 

It is in just such cases as these described that the co-operation of a 



PREUMINARY CONSIDERATIONS. 175 

skillful physician is indispensable. A case was recently noted in 
this city where, from a prolonged operation in regulating, a delicate, 
puny lady was invalided for two years, solely by the shock pro- 
duced upon a nervous system primarily unstable. 

IV. DESIKE FOR CORRECTION. 

Success in dentistry as well as in medicine depends to some extent 
on the attitude of the patient. The mysterious influence of the 
mind over the body can be made a great aid in accomplishing an 
operation or else it may be a decided drawback. 

Knowledge of human nature, quick sympathies, an agreeable 
presence and tact are among the most valuable possessions of the 
operator. If we work in harmony with the laws of health, half is 
gained. With the aid of these qualities we will be more likely to 
gain the co-operation of patient and guardian. 

Desire for correction depends somewhat on the social status of 
the patient, sex and age. The very poor, even if they have a decided 
aesthetic sense, are so hampered with pressing considerations of a 
more urgent nature that they will pay little attention to an irregu- 
larity. With the well-to-do this is quite different. The ornamental 
side of life assumes larger proportions. Beauty is of the greatest 
importance, especially to women. Their lot in life may be mater- 
ially changed by an attractive mouth. It is not for us to question 
the right or wrong of this state of things ; we must consider simply 
facts. Society takes these things for granted and acts upon them. 
This being so, the dentist is more likely to secure the co-operation of 
the child of the well-to-do. Since the daughter of Dives subjects 
herself most cheerfully to the torture of compressing her waist, she 
will with equal readiness subject herself to the irritation of correct- 
ing a deformed arch, and with much better reason. The mouth, 
with its ample opportunity for display in its various moods of repose, 
conversation or laughter, suffers less from the ravages of time than 
the waist. Mothers are usually keenly alive to these considerations 
and encourage their children to endure the strain. Occasionally, 
however, there are parents who, by their indifference or careless 
remarks, become a great hindrance to the dentist. They do not co- 
operate with him by seeing to it that appliances are worn and that 
visits are regular. From these considerations it follows that the 
dentist should find out what the attitude of patients and guardian is 



176 IRREGULARITIES OF THE TEETH. 

before he undertakes the task, for without their co-operation his best 
efforts will be thwarted and his reputation even may suffer. 

V. IMPRESSIO^^S OF THE MOUTH, AND MODELS. 

Taking the impression of the mouth and jaws is, of necessity, the 
first step in regulating the teeth. To secure a counterpart of the 
mouth sufficiently accurate for reference and study, S3 that when a 
model is examined it will show the exact contour of the irregularity, 
requires much care. The position of the teeth, their relations to 
one another, and the conformation of the jaws can be more easily 
studied, and accurate conclusions more readily deduced, from the 
cast than from an examination of the mouth itself. It is not only 
essential that the teeth should be moved to their proper places, but 
they must be in harmonious relations to one another ; otherwise, 
they will be inclined to return to their faulty positions ; and their 
normal relations can best be determined by studpng the model. 

Impressions may be taken in plaster of Paris or in the modeling 
compound, but the material employed should depend to a great 
degree upon the shape of the jaw and the position of the teeth. If 
the teeth are but slightly irregular, or if the crowns are short and 
quite irregular, plaster of Paris should be used, as it can be removed 
from the mouth with but little disturbance of the impression. 

If, on the other hand, the teeth are irregular and long, and the 
arch deep, plaster of Paris will be apt to adhere to the teeth ; in this 
event only the impression cup will come away, and, as a consequence, 
the plaster will have to be cut out. In such cases the modeling 
compound should be used. 

Where the plaster is used the patient should occupy an ordinary 
chair instead of the operating chair, as the head is lower and the 
operator can have better control of the patient. Protect the cloth- 
ing by placing two towels under the chin and a newspaper in the lap. 
Select an impression cup large enough to enclose the teeth, and 
build it up with wax so that it wiU extend beyond the margin of 
the gums ; fill the centre of the cup with soft wax to conform to the 
palate ; and the plaster will be readily carried to all parts of the 
mouth. Take a quantity of the finest quality of plaster, and mix 
it in a bowl with sufficient water to make a mixture of the consis- 
tency of thick cream ; the addition of a little salt will hasten the 
process of setting. After stirring until the air bubbles have disap- 



PRELIMINARY CONSIDERATIONS. 177 

peared and the plaster has begun to set, fill the cup and outer edges 
with it. 

The operator should stand to the right of and just behind the 
patient, with the left arm around the left side of the head, and the 
forefinger inserted into the mouth. Carry the cup to the mouth 
with the thumb and forefinger upon the handle and the middle fin- 
ger in the centre to steady it, and after it has been inserted into the 
mouth, with a rotary motion of the right hand press it into place, at the 
same time raising the lip and pressing out the cheek with the left 
finger. When the cup is in position, hold it firmly with the middle 
finger in the centre of the plate against the teeth. Incline the head 
towards the breast to prevent the plaster passing back to the fauces. 
Should the stomach become disturbed and vomiting ensue it can be 
evacuated without interfering with the impression. 

Test the plaster in the bowl or on the impression cup, and when it 
will break with a clean fracture it is time to remove the cup, which 
can be done by moving the cup backward and forward with the 
right hand, and pushing out the cheek with the fingers of the left 
hand to admit the air. Having placed it in the upper towel, held 
up by the assistant, carefully examine the mouth, and if pieces of 
plaster are seen, put them in the towel on the proper side of the im- 
pression to save time, and set it carefully away, afterwards arrang- 
ing the pieces in their right places in the impression. 

The second towel is for the purpose of removing plaster that may 
remain about the face. 

It is well to explain something of the operation to the patient, as 
one would naturally anticipate a more serious experience than is 
actually realized. All of these little details should be strictly at- 
tended to, in order to insure a perfect impression at the first sitting, 
and thus save the patient the annoyance of several applications. 

In taking impressions of the lower jaw the patient should sit 
higher, so that the mouth will be on a level with the elbow of the 
operator, who stands in front of the patient ; the fingers of the left 
hand should push out the cheeks and lips while the cup is ro- 
tated into place with the right hand. The first and second fingers 
of each hand should rest upon the cup over the bicuspids and 
molars, the thumbs under the jaw on either side, thus holding the 
cup firmly in place until the plaster sets, when it should be re- 
moved and placed in the towel as before. After a few minutes' 
12 



178 IRRKGUI.ARITIES OF THE TEKTH. 

hardening, the impression should be placed under running water 
to remove mucus, saliva, blood or particles of plaster. Should the 
plaster be broken, the pieces can be placed in the positions indi- 
cated by the arrangement on the towel, and, when perfectly dry, 
fastened together by melted black wax. A clean separation of 
the model is obtained by covering it with a lather of soap and 
washing oif the surplus, or by coating with shellac and oiling to 
prevent sticking. 

The author has used modeling compound with success by heat- 
ing water to the boiling point and then pouring it in a bowl 
containing modeling compound. The compound should be in- 

FiG. 105. 




sorted as hot as it can be borne ; enough should be used to cover 
all parts of the teeth and jaws when it is forced into place. The 
impression cup should be held firmly in place for a moment, 
and a towel saturated with cold water should be carried to all 
parts of the mouth to chill the compound. S. S. White's upper 
and lower impression cups, No. 17 and 18, such as are illustrated 
in Figs. 105 and 106, should be used in taking impressions in 
cases of irregularities. The compound loses its elasticity by boiling. 

It is a good plan to oil the surface of the impressions, thus 
preventing the compound sticking to the cast. 

To obtain the model, place a sufficient quantity of water in a 
bowl and pour in plaster, allowing jt to settle, and thus prevent- 



PREI.IMINARY CONSIDERATIONS. 



179 



ing the formation of air bubbles ; add enough plaster to make it of 
the consistency of cream. Put a drop of water into each depression 
made by the teeth in the impression, to exclude the air, and add a 
small additional quantity of plaster. By tapping the cup upon the 
bench the plaster will fill up the depressions without the formation of 
air-bubbles ; the surface should now be covered with plaster, and 
after mixing in more dry plaster to make it thicken, fill the impres- 
sion full and place it upside down on a glass slide. Now build out 
the model until even with the impression cup, and allow it to harden. 
It is better to let it stand from twelve to twenty-four hours, that it 
may become thoroughly hardened before being removed. 

Fig. 106. 




Having removed the impression, trim the model roughly, and after 
articulating, trim it so that the body of the model will be parallel 
with the line of the teeth, and made presentable for inspection. 
Place the name of the patient and the date of the time the operation 
was begun on the surface of the lower model, and the patient's ini- 
tials upon the upper model, after which the surface should be var- 
nished. A band of elastic rubber will hold them together, or make 
an articulator of brass wire, as illustrated in Fig. 107 for the pur- 
pose of holding the models in their proper positions, thus preparing 
them for easy inspection. The upper arms and spiral are made of 
one piece of wire. No. 18, U. S. gauge. The lower arms are made 
from another piece of the same wire passed through the spiral and 



180 IRREGULARITIES OF THE TEETH. 

bent to correspond to the upper arms. The models are now articu- 
lated, and the wire arms bent to meet the upper and lower surfaces. 
The surfaces, after being saturated with water, should be covered 
with plaster and the arms united to the model. 

Fig. 107. 




The cups for taking impressions of the anterior teeth, illustrated 
by Fig. 108, and for the molars and bicuspids. Fig. 109, together 
with suggestions for their use, were deWsed by Dr. Wm. P. Cooke, 
of Boston. He prepares a sufficient quantity of wax, and after 



Fig. 108. 




warming it, places it upon the cup. When the jaws are in a nor- 
mal position, and the saliva and mucus removed from the teeth and 
mucous membrane, the cup with the wax is forced between the lips 
and against the teeth and cooled with a wet napkin. The patient is 



PRELIMINARY CONSIDERATIONS. 



181 



requested to open the mouth, when the impression is removed, as 
shown in Fig. 110. The model, Fig. Ill, is obtained by pouring 
plaster into both upper and lower impressions, thus making a solid 
model. This is a very desirable way of procuring an accurate and 
permanent model of the mouth when one is needed for observation 




and study. It will save time to put them in a place convenient for 
reference, which receptacle should, of course, be a safe one. The 
models should be examined from time to time, to note the progress 
of the operation. 

Fig. 110. 




VI. THE STUDY OF MODELS. 

It is important in regulating teeth to have a model conven- 
iently near at hand to be able to improve spare moments by study- 
ing it, and thus become thoroughly acquainted with the physiologi- 
cal conditions of the teeth, before attemping to come to conclusions 
regarding the pathology of the case. In determining the character 
and extent of a deformity some criterion is necessary. In the human 



182 



IRREGULARITIES OF THE TEETH. 



skull, taking the two cuspids for our starting-point, we find the arc 
of a circle, and by dropping a line from the cusp of the cuspid to 
the center of the wisdom-tooth, we see that the posterior part 
diverges considerably fi-om the central line. Thus, Fig. 112 shows 
the three normal lines of the dental arch. 

The incisors of the inferior maxilla should close inside of the 

Fig. 111. 




superior incisors, and the buccal cusps of the bicusj^ids and molars 
should occlude at the centre line or sulci of the superior biscuspids 
and molars. If we hold the articulated skull in our hands, with the 
buccal surface toward us, we will obsen'e a gentle curve downward 
from the cuspid to the second bicuspid, then rising until the wisdom 

Fig. 112. 




After Farrar. 



teeth are reached; thus, Fig. 113 not only shows the relative posi- 
tions of the teeth in the jaw, but their relation to one another. As 
mastication is done principally by the bicuspids and first molars, it 
is necessary that these teeth articulate perfectly, which is accom- 



PRELIMINARY CONSIDERATIONS. 183 

plished by the tooth of one jaw interlocking between two teeth of 
the opposite jaw, thus providing support and surface. 

If the arch posterior to the cuspids be uniform, and these teeth 
are regular and articulate as shown in the cut, they should not be 
interfered with for a slight deformity existing in any of the six ante- 
rior teeth. The cuspids may be spread laterally to make all the room 
necessary. When this is accomplished and the deformity corrected, 
all the teeth in the arch will adjust themselves properly. If the 
irregularity be complicated, and more room required than can be 
obtained by spreading the cuspids, it is best to enlarge both arches ; 
this will give all the space needed. To change a well-articulated 
set of teeth so that the cusps of the opposite teeth will strike would 
be unpardonable. 

The arch of the superior and the inferior maxilla should have a 

Fig. 113. 




diameter of sufficient width to prevent an impression of the teeth 
on the sides of the tongue. Any deviation of the jaws or teeth 
from this outline is considered a deformity, and should receive the 
attention of the dentist. 

Examining the model with this ideal in mind, we find certain 
deformities, and the question arises how to treat them. Before pro- 
ceeding, we will decide, on careful consideration, that one of two 
conditions exists : either the teeth are in a crowded and irregular 
condition inside of the proper line, or they are isolated and irregu- 
lar outside of the line. In the majority of cases the irregularity 
involves the teeth anterior to the first permanent molars. If space 
be wanting, the question will arise whether to enlarge the arch by 
force, or to extract one or more teeth, and thus give the required 
room. The age of the patient will, to a certain extent, decide this 
question. If the temporary teeth are in the mouth, causing irregu- 
larities, they must be removed. When the removal of the second 



184 IRREGULARITIES OF THE TEETH. 

teeth becomes a necessity, a tooth should be selected which is the 
least prominent or which will least affect the expression. A good 
rule is to retain, if possible, the six anterior teeth. As the cuspids 
are the most prominent and give expression to the face, they should 
never be removed ; but if one must be sacrificed, the selection lies 
between the first or second bicuspid and the first molar. 

If we find on examination that the teeth are decayed (at the age 
of twelve or thirteen years it is common to find the first permanent 
molar decayed), those affected should be extracted if the crowns are 
wholly or partially destroyed. In the model of the upper teeth of a 
girl fourteen years of age (Fig. 114), the bicuspids are seen to have 

Fig. 114. 




advanced so far forward that there is insufficient space for the cus- 
pid to come down into place. Upon examination of this case it was 
found that the first bicuspid upon the left side and the first perma- 
nent molar upon the right side were badly decayed. It was easy to 
decide which teeth should be sacrificed. The cuspid upon the left 
side came into place without assistance. The bicuspids upon the 
right side were carried back and the right cuspid came into place. 
It is probable that in the past the first permanent molar has often 
been extracted without sufiicieint cause. As this tooth serves an 
important purpose in mastication on account of its broad surface, I 
should advise its retention if the crown be in a fair state of preser- 
vation. It has served for six years, which fact, in connection with 
its solidity in the jaws and its central position , is an argument in 
favor of keeping it as long as possible. 

Upon examining the models of the jaws, w^e occasionally find the 



PRELIMINARY CONSIDERATIONS. 185 

articulation posterior to the cuspids perfect, with the cuspids nearly 
approximating the centrals, and the laterals locked inside of the 
arch. Whether they are sound or decayed, it may be best in such 
cases to remove one or both laterals. The general appearance of 
the teeth will not be injured by this treatment. Dr. Guilford, in 
the " American System of Dentistry," mentions two cases of this 
kind, as follows : " The writer had two cases in one year presented 
to him for the reduction of prominence in the superior front teeth. 
In each case there was a broken or badly-diseased right central that 
was past hope of redemption. In these cases it did not happen par- 
ticularly amiss, for the extraction of the roots afforded room for 
drawing in the remaining five teeth, thus easily reducing the de- 
formity, and at the same time closing the space made by their loss. 
The appearance of the patient in each instance was greatly im- 
proved, and the absence of even so large a tooth as the central was 
scarcely noticeable. 

" In another case, a girl eleven years of age had lost a right supe- 
rior central incisor through a fall from a swing. Two days after 
the accident, and when the tooth had been mislaid or thrown away, 
she was brought for treatment. Only two methods of remedying 
the difficulty suggested themselves. One was the wearing of an arti- 
ficial tooth, the other drawing the teeth together to close the space. 
The latter plan was decided upon, and successfully carried into 
effect, but, unfortunately, as there had been no protrusion formerly, 
and there was contraction afterward, the superior teeth no longer 
overlapped the lower ones, but met them edge to edge, thus giv- 
ing the upper jaw a flattened appearance which was, in itself, a 
deformity. The patient was saved the annoyance of wearing an 
artificial tooth, but her facial expression was injured in conse- 
quence." 

Irregularities of the inferior incisors are often seen, and if the 
articulation be normal in the posterior part of the mouth, almost 
any of the incisors that are out of position may be removed. They 
resemble one another so closely in size and shape and are so nearly 
concealed by the lip that their loss will not be observed. The 
author would suggest that the operator needs to be particularlv 
careful in deciding upon the mode of treatment, as he has seen three 
cases in which an actual increase of the deformity was produced by 
a hurried operation. In one of these, a girl ten years of age, a cen- 



186 IRREGULARITIES OF THE TEETH. 

tral incisor was removed, and the muscles of the lip, together with 
lateral pressure of the adjoining teeth, pushed against the cuspids, 
forced the incisors into a crowded condition, thus producing a 
V-shaped arch. It was ascertained that the articulation of the pos- 
terior teeth was not perfect. It has been advised by some authori- 
ties to remove a corresponding tooth on the opposite side where 
want of room compels the removal of a tooth in the anterior part of 
the mouth. They claim that there is danger of the incisor moving 
by the median line when a tooth from one side only is extracted ; 
but we have found that when a tooth is removed back of the cuspids, 
it is seldom that the lateral pressure is sufficient to materially move 
the incisors. 

In considering the bicuspids, the one which is the most decayed 
should be removed if, by doing so, the irregularity can be corrected. 
Care should always be exercised in examining the occlusion before a 
bicuspid is extracted. The author has seen a case where the two 
upper second bicuspids were extracted with the hope of relieving the 
crowded condition of the anterior teeth. The articulation of the 
first bicuspids was such that an adjustment was impossible, these 
being perfectly interlocked with the lower teeth. No relief fol- 
lowed, and the only way to correct the blunder was to move the first 
bicuspids back. The mistake was made by following blindly what 
was vaguely supposed to be the rule without considering the require- 
ments of occlusion. 

If both bicuspids are sound, then the first should be chosen 
if the anterior teeth are crowded. This makes room for the cuspid 
if this is desirable. In studying the model, the end to be kept in 
view is the retention of the teeth in place after they have found their 
new position and are properly articulated, so that they will hold one 
another in place. If this be not accomplished, the action of the 
cusps will force the teeth into their original faulty position. 

VII. FEES. 

In most cases an important consideration in the operation of 
regulating a set of teeth is the pecuniary reward for it. The 
specialist in this particular branch should have so prepared himself 
that he will fully understand and appreciate the requirements of 
any case which he may undertake to correct. To do this will take 
much time and anxious thought, for which he should receive a just 



PRKLIMINARY CONSIDERATIONS. 187 

reward. A thorough understanding as to the proper remuneration 
for the operation should be established between the dentist and his 
patient before anything is done. 

The models of the jaws should be carefully examined. The tem- 
perament and disposition of the patient, as well as the ossific con- 
dition of the jaws, should be considered and minutely inquired into. 
For it will frequently happen that mouths exhibiting very nearly 
the same deformity will, on account of mental and physiological 
idiosyncrasies and great difference in density of tissue, require very 
different treatment in order to accomplish equally favorable results. 
After these preliminaries have been carefully attended to, as correct 
an estimate as possible should be made (and at the best it can but 
approximate) of the expense of regulating the teeth and securing 
them in their proper position. 

At this juncture, and before any operation is begun, a thorough 
understanding should be established between the operator and the 
parent or guardian of the approximate cost of the work. It is well 
not to be too definite in regard to the matter; for it will frequently 
happen that the operation will require very different appliances and 
consume more time than was at first anticipated, in which case the 
operator should be rewarded for his unexpected labor. Or, the 
operation may be completed in a much shorter time than was anti- 
cipated, in which event a proper regard for the patient's rights 
should prompt a reduction in the fee. A minimum and a maxi- 
mum price, therefore, should be agreed upon before the operation 
is undertaken. Conspicuous among the difficulties which come 
with regulating is, first, to persuade the patient to submit to the 
annoyance of wearing the appliance ; and, secondly, to impress 
upon the patient the necessity of being prompt and faithful in 
his visits to the dentist. Not appreciating the importance of 
these operations, patients, and especially children, frequently be- 
come discouraged, and are anxious to abandon the treatment be- 
fore it is completed. The parent too often sympathizes with the 
child, and Avithout regard for the labor or expense which the 
dentist has assumed, or the real interest of the patient, the opera- 
tion is abandoned. The dentist is left without remuneration, al- 
though up to this point he has carried out his part of the con- 
tract. To secure the continued co-operation of the patient and 
parent until the completion of the operations, it is but justice to 



188 IRREGULARITIES OF THE TEETH. 

the dentist that he should demand and receive at least one-half of 
the proposed fee before the work is begun. With this money in- 
vested in the operation, the parent will be loth to allow the case to 
be abandoned before it is finished. 

The dentist should, with due regard to the comfort and good of 
his patient, do all in his power to expedite his operation, so that the 
suffering and expense may be as light as possible ; but whatever he 
does should be done with an intelligent understanding of the physi- 
ological and pathological conditions with which he is dealing. The 
patient should, by obedience to the dentist's instructions, do all in his 
power to facilitate the correction, which will, as a matter of course, 
greatly reduce the expense of the operation. As a rule it ^^-ill be 
better not to be too minute in detailing the plans intended to be fol- 
lowed and the appliances to be used in the course of the operation 
for it will frequently happen that the most carefully-planned pro- 
cedure will have to be varied during the operation ; in which case 
disappointment and dissatisfaction might be engendered in the mind 
of the patient, and lead to a suspicion as to the dentist's ability to 
accomplish the results at first promised. 



CHAPTER II. 

PHYSIOLOGICAL AND PATHOLOGICAL CHANGES. 

It is apparent, to a close observer, that the teeth are constantly 
changing their positions in the jaw, absorption and deposition of bone 
going on simultaneously and continuously. This is particularly 
noticeable at the first eruption of the teeth, and again from the 
twelfth to the sixteenth year. When the first permanent molar has 
been removed the second and third gradually press forward and fill 
the space. 

It will also be noticed that teeth that are erupted out of their posi- 
tion will, in time, often find their way into their proper places ; also 
when the molars and bicuspids are lost late in life the anterior teeth 
are forced forward, thus causing the alveolar arches to project. 
Again, it is found that when the anterior teeth come in irregularly 
they rotate their way into place. These facts indicate that when na- 
ture is assisted, whether by mechanical devices or the removal of ob- 
structions, the regulation of malpositions becomes both simple and 
logical ; and, furthermore, that after regulation, the teeth may be 
firmly retained in their relatively new positions in the alveolar pro- 
cess. 

It stands to reason that the application of light, constant pressure 
to irregular teeth, in connection with nature's own efforts, will greatly 
enhance the physiological phenomena of absorption and reproduction 
of bone. Whether these phenomena will proceed equally or not will 
depend upon the amount of pressure exerted and the condition of 
the individual, for it is obvious that in cachexise of various kinds dis- 
integration is favored, while tissue-building is correspondingly slug- 
gish. This will serve to impress the immediately vital importance 
of the degree of pressure and the constitutional condition of the 
patient in various operations of regulating. When the whole of the 
alveolar arch is spread laterally, and the force is distributed for a 
distance upon both sides of the jaw, the bones yield to a certain ex- 
tent, thus spacing the teeth equally in all directions ; and by ab- 
sorption of the old and deposition of the new bone about them, they 

189 



190 IRREGULARITIES OF THE TEETH. 

become fixed in their new positions. The degree of absorption and 
change of position is not always equal in all parts of the same tooth, 
varpng chiefly with the direction of the pressure. 

When force is applied to the crown, and the tooth has to be moyed 
considerably, there is more absorption at the margin of the alyeolus 
than at its apex. Simple leyerage will explain this : the mechanical 
appliance is the power, and the apex of the tooth is the fiilciiim ; 
naturally, the power acts upon the margin of the cayity in which the 
tooth is imbedded. Or it might be said that the tooth moyes like a 
spoke in a wheel : the outer part of the crown trayels a relatiyely 
greater distance than the inner part, or apex. The gradual dimi- 
nution in diameter from neck to apex is also an important consider- 
ation. 

AVhen the pressure is too great, then absorption is arrested, on ac- 
count of the inflammation and pain which result. The operator 
should ayoid causing pain, and this is usually possible. When pain 
does occur, it should warn him that the line of demarkation between 
physiological and pathological changes is being transgressed by me- 
chanical ^^olence. If the pressure be gentle, eyenly distributed and 
constant, no pain will be experienced after the teeth haye once begun 
to yield in the proper direction. But when the force is applied, re- 
moyed, and reapplied at spasmodic inten^als, considerable pain must 
necessarily result. 

The difference between the effects of steady and those of intermit- 
tent pressure is illustrated in eyery-day practice : where teeth have 
been separated to facilitate the filling of proximate cayities, the vi- 
bration of the teeth caused by preparing the ca^^ty and applying the 
gold, produces intense pain, which is relieved by inserting a wedge 
to distend and steady the teeth by its constant and equable pressure. 
Individual susceptibility must not be forgotten in this connection ; 
for, as is well known, the impressibility to pain and the power of en- 
durance vary ^rith the temperament and condition of the patient. 
After the age of twenty-five or six the bones contain more of the 
earthy and less of the animal matter than during the formative and 
developmental period, and the constructive stage having passed, it 
becomes more difficult to move the teeth than in earlier life ; and, 
pari passu, with the increased pressure required to effect absorption, 
a greater degree of pain and inflammation is produced. 

In these latter cases of regulating, retentive plates must often be 



PHYSIOI.OGICAI. AND PATHOI.OGICAI. CHANGES. 191 

worn, after the malposition of the teeth has been corrected, for two 
or three years, until a deposition of bone takes place which is suffi- 
ciently firm to hold the teeth securely in place. The teeth most dif- 
ficult to retain are those that have been rotated in the jaw, as they 
have a tendency to return to their original and faulty positions, even 
after a lapse of three years. By dispensing with the retentive plate 
for a day or two, and then reinserting it, any deviation in position 
can be readily noted. 



CHAPTER III. 

MECHANICAL FOECES. 

In order to do the work with the least loss of time and incon- 
venience to the patient, it is necessary that there should be a 
knowledge of the mechanical forces, the powers and limitations of 
each, and method of application. All forces act either continuously 
like the lever, or interruptedly like the screw, but, in both cases, their 
action diminishes with the yielding of the tooth. The mechanical 
powers are all modifications of two primary principles : the inclined 
plane and the lever. From these other forces are derived, thus : 

1. The Lever. 4. The Inclined Plane. 

2. The Pulley. 5. The Wedge. 

3. The Wheel and Axle. 6. The Screw. 

Elasticity, as shown in India-rubber and the spring of metals, 
although not classified with the primary forces in mechanics, plays 
an important part in the application of force in regulating teeth. 
When these laws and their applications are firmly fixed in the 
mind of the operator, he can readily take advantage of the one 
which should properly be applied, or, when necessary to apply 
more than one, can combine them in such a manner as will best 
accomplish the desired result. The degree and line of force re- 
quired have much to do with the form of appliances which should 
properly be used. 

APPLICATION OF FOKCE. 

In every appliance for regulating the teeth the object is the 
same, viz., to exert pressure upon the teeth to be moved. Any ap- 
pliance for this purpose should be as small as is compatible with 
effectiveness and strength. When possible, it should be so con- 
structed that it can be applied inside of the arch in such a manner 
that it will not interfere with speech or mastication, and can be 
removed by the wearer for cleansing. 

It should give as little annoyance and pain as possible, and 
should not necessitate frequent visits to the dentist for its adjust- 
ment. Whether the teeth are to be forced out or drawn in, there 
192 



MECHANICAI. FORCES. 193 

are always to be considered a body to be moved (the tootb) and a 
fixed point of resistance. 

Study of the model does not always determine the amount of 
force required to move the tooth. This statement is not made to 
discourage the study of the model, but to encourage caution. 
Though usually a point opposite can be chosen for the anchorage 
of the appliance, this rule does not always hold good. Every case 
is a problem in itself. The point of anchorage must, of course, 
afford greater resistance than the point to be moved, and to find 
such a point is sometimes a diflicult manner. Such is the case 
when a cuspid is to be moved. In such cases it frequently happens 
that the dentist finds, to his chagrin, he has moved his point of re- 
sistance rather than the tooth determined upon. From this it fol- 
lows that constant vigilance must be exercised in noting occlusion, 
and the patient should be asked in which tooth he suffers most. It 
is often found expedient in moving teeth that afford great resistance, 
like central incisors or cuspids, to loosen them first by simple wedg- 
ing with orange w^ood, or even cotton, proceeding slowly. Thus the 
resistance is lessened and the tooth or teeth to which they are attached 
will now afford greater resistance in proportion than at first. 

Sometimes a plate can be constructed to which an appliance for 
moving a tooth can be attached. This is desirable (1) where there 
is no tooth conveniently located for attachment, [T) when it is 
expedient to avoid the additional irritation, (3) when the mechan- 
ism is such as to require it. In applying the apparatus to a tooth, 
its position in the jaw should be observed and the inclination of the 
root or roots must be ascertained to decide whether they stand per- 
pendicularly in the alveolar process or on an incline. All obstruc- 
tions should be removed by extraction or by lateral pressure. 

The force should be applied to the tooth to be 
moved either at right angles to the long axis of the 
root (Fig. 115, a 6 c), or at an angle of 45 degrees, 
d b c. By these means the tooth is prevented from 
rising from the socket. The position of the tooth in 
the jaw, the density of the alveolar process, the 
length of the roots, their normal or abnormal condi- 
tion and length of crowns, will all require considera- 
tion in deciding the amount and direction of the 
force which may be used w^ithout elongating the tooth. 
13 




194 IRREGUI.ARITIES OF THE TEETH. 

If the superior maxillary bone be examined after the teeth are 
removed, it will be seen that the outer plate of the alveolar process 
of the superior maxilla is much thinner than the inner plate, which 
is backed up by the strong, thick bone of the hard palate, while 
upon the inferior maxilla the outer plate of bone is thinner as far 
back as the second bicuspids, and the inner plate is thinner at the 
part occupied by the molars. The inner plate is thickest between 
the second bicuspids upon either side, and is reinforced by the 
symphysis and gential tubercles. The external plate is thickest in 
spaces occupied by the molars, and is backed by the external ob- 
lique ridge. When the soft tissues have been removed from the 
superior maxilla, it is not uncommon to find the roots of sound, 
healthy teeth extending through the outer plate of bone. After 
the teeth have been extracted, absorption of the outer plate takes 
place much more rapidly than of the inner plate. Absorption of 
the external and internal plates of the inferior maxilla goes on 
more uniformly than in those of the superior, owing to a more even 
distribution of bone. 

In the application of force, it will be observed that the most 
pressure is required in the direction of the greatest resistance, and 
care must be exercised in directing the force toward the weaker 
parts of the alveolar process. 

If possible the force should be uniform and steady, but this is 
possible only with certain appliances like the elastic band, ligatures 
and the like, while impossible with the screw. All forces act either 
slowly and constantly like the above, diminishing ia their action in 
proportion to the yielding of the tooth, or else they act by im.pulse, 
like the screw. 

The force exerted should be enough to produce absorption of 
bone without causing inflammation, although in some cases slight 
inflammation is desired. Here we would discountenance the too 
rapid movement of teeth, especially when persons are over twenty 
years of age. I have seen the alveolar process absorbed to such an 
extent that it was impossible to retain the teeth in their proper 
places, as new material was not deposited. I would protest de- 
cidedly against the drilling of holes in natural teeth for anchorage, 
as is practiced by some reputable dentists. There are few cases 
that cannot be treated by securing a band or cap of thin gold or 
platinum to the teeth with oxyphosphate of zinc, in which holes 
may be drilled or hooks or loops soldered at any required point. 



MKCHANICAI. FORCES. 195 



THE LEVER. 

The lever " is an inflexible bar, capable of being moved about a 
fixed point, called the fulcrum." 

The resistance or weight is the object to be moved ; the fulcrum is 
the fixed point of support ; the power is the force which overcomes 
the resistance. According to the relative position of these, we have 
three kinds of levers : 

1. Lever of the first kind : Power— Fulcrum — Weight. 

2. " " second kind : Power — Weight — Fulcrum. 

3. " " third kind ; Weight — Power — Fulcrum. 

An example of the first kind is the crow-bar ; of the second, the 
wheelbarrow ; of the third, the forceps. 

General Law. — Intensity of force is gained, and time is lost, in 
proportion as the distance between the poiver and the fulcrum exceeds 
the distance between the weight and the fulcrum. 

In using the lever for the correction of irregularities it undergoes 
modifications. Thus when it is applied in the form of a ligature or 
an elastic band it becomes flexible instead of rigid, the fulcrum 
frequently becomes a surface instead of a mere point, and the power 
is changed into resistance. 

Where the leverage can be multiplied most stubborn cases are 
obliged to succumb, as is illustrated in rotating teeth set very firmly 
in the jaw, or those which are crowded closely, or teeth of persons 
in advanced years, where the alveolar process has become very 
dense and hard. The increase of power in the lever is obtained by 
lengthening the rod proportionately or in combining the leverage 
with another force. 

The application of an increased length of rod is limited, for want 
of space in the mouth ; for if above rather limited dimensions it 
interferes with the tongue or lips. We invariably use the lever in 
any cavse in which the anterior superior teeth occlude inside of the 
inferior teeth, if the case be presented early enough. It is always 
desirable to regulate these teeth as soon after their eruption as possi- 
ble, i.e., before the bony tissue becomes dense and hard. Fig. 116 
illustrates this simple method. 

Here we have a lever of the first kind. The upper incisor that 
strikes inside is the weight to be moved, the lower incisor against 



196 



IRRKGUI.ARITIES OF THE TEETH. 



which the stick rests is the fulcrum aod the hand holding the stick 
is the power. The greater the distance between the hand and the 
resting-place of the stick the greater the force exerted. As soon as 
the upper tooth strikes outside the lower the operation is completed 
on the principle of the wedge. Every time the patient closes the 
teeth with any degree of force, the wedge (the lower incisors) is 




Fig. 117. 



driven a little farther under the upper, thus forcing it outward until 
even with the rest. 

Another simple and efficient device, acting on the principle of 
the lever for bringing out one or two teeth, is a 
strip of German silver bent at an angle once or 
twice (Fig. 117). This affords double leverage, 
inasmuch as it draws one tooth in and the other 
out. B is the weight, the proximal surfaces of 
the two adjoining teeth at c are the fulcrum and 
a the power, or a the weight, c the fulcrum and 
The strongest tooth affords, of course, the greatest 
resistance and is therefore the power. 

The resistance or power in cases like this depends largely on the 
elasticity and tenacity of the metal. If the intervening medium 






b the 



power. 



MECHANICAL FORCES. 197 

between the proximal surface of the resisting tooth and that of the 
tooth to be moved has little or no elasticity, the intervening medium 
will yield readily, and nothing can be accomplished. 

The simplest form of leverage is a wedge of cotton, gutta perch a 
or wood. The yielding tooth becomes the weight, the resisting 
tooth the fulcrum and the elasticity of the intervening wedge the 
power. We thus have a lever of the third kind. When cotton or 
wood are used capillary attraction becomes the source of power, 
inasmuch as it results in the absorption of moisture. 

Leverage depends for its efficiency on the point where it is ap- 
plied. Judgment and thought exercised in this will amply repay 
in the time gained and pain saved. In case the tooth a is to be 
brought in, it is a matter of some consequence whether force is 
applied half-way between the cutting-edge and the neck or at the 
cutting-edge. The apex of the root always being the fulcrum, the 
farther from this we can apply it, the better ; hence it is desirable 
to apply it as near as possible to the cutting-edge. A tooth with a 
long root furnishes the advantage of distance from the fulcrum, 
which is, however, more than counterbalanced by the additional 
resistance thus offered, as it is easier to move a tooth with a short 
root. 

THE PULLEY, WHEEL AND AXLE. 

The pulley is a wheel with a groove cut into its circumference, 
and is movable upon its axis. In mechanics the common term for 
pulley is sheave. The pulley or sheave is placed between the ob- 
long blocks of wood through which the axis passes and supports 
the pulley in the centre. The cord passing around the pulley is 
called the tackle. The bucket and weight in the old-fashioned well 
illustrate the pulley. The wheel and axle is a modification of the 
pulley. The wheel is fastened securely to the axle ; the weight is 
attached by a rope to the axle, and the power by a rope to the 
wheel or to handles fixed at right angles to its rim. The steering- 
gear of a vessel is an illustration of this kind of lever. 

The wheel and axle and pulley are modifications of the lever of 
the first kind, the circumference of the wheel or pulley correspond- 
ing to the long arm ; the axle or block to the short arm, the axis 
in both cases the fulcrum. The general law corresponds to that 
of the lever. 

Law. — Intensify of force is gained and time is lost in proportion as 




198 IRREGULARITIES OF THE TEETH. 

the circumference of the wheel exceeds that of the axle. The advantage 
of the wheel and axle over the simple lever is the change of direc- 
tion of power which it affords. The power, instead of being in the 
same straight line with the fulcrum and weight, may be applied at 
an angle. This is convenient in producing the rotation of a tooth. 

In its application to regulating, the elasticity of the rubber band 
is the power ; the tooth or teeth over which it passes is the fulcrum, 
and the tooth to be moved the weight. 

Fig. 118 illustrates the rotation of a tooth by having a gold band 
Fig. 118. with au arm fitted to the tooth, and a rub- 

ber band attached to the arm and stretched 
C*^t^^^^ *^ ^^® ^^^^ bicuspid ; as the tooth rotates, 

""'^Iw^^ *^® ^^'"^ ^® ^^^^ ^* right angles to the 

band. This application of the wheel and 
axle w^ill accomplish the rotation of the 
teeth in the majority of cases. The diffi- 
culty lies in the retention of the teeth after 
they have been forced into their proper 
position. The younger the patient, the easier this will be accom- 
plished. 

It should be observed that the powder of an elastic band is in- 
creased with the tension until this becomes greater than the strength 
of the material, when it will break. Hence the greater the number 
of teeth over which it passes, the go-eater the power of the same 
band ; but at the same time it is lessened by the friction of the sur- 
faces over which it passes. 

THE INCLINED PLANE. 

The inclined plane — a plane surface inclined to the horizon at 
any angle— is used for raising weights. The longer the inclined 
plane the easier it is to raise a body a given height. 

General Law. — When the power acts parallel to the inclined 
plane, intensity of force is gained and time is lost in proportion as 
the length of the plane exceeds its height. 

■' In its application to dentistry this force is of especial value in 
cases in which the arch is to be widened by an appliance ; under 
such circumstances the teeth exert an outward pressure on the op- 
posite jaw, and the articulation of the cusps makes an inclined plane. 

If the anterior superior teeth close inside of the inferior teeth 



MECHANICAI. FORCES. 



199 



they should be brought out with the lever, and if the inferior teeth 
are too short to exert a pressure on their opponents, they may be 
fitted with a platinum cap and cemented securely with the oxy- 
phosphate of ziuc. This arrangement will maintain a constant out- 
ward pressure upon the superior teeth. Fig. 119 is another illus- 



FiG. 119. 




tration of this principle. In this case a metal plate is fastened to 
the teeth by a ligature instead of an elastic band. 



THE WEDGE. 

The wedge is a modification of the inclined plane. The power is 
applied with a hammer or a sledge to the back of the wedge. It is 
employed in various ways in ordinary mechanics, as in raising build- 
ings, splitting wood, etc. It is an unsatisfactory force to calculate 
upon, because the large, flat surfaces produce so much friction. On 
the other hand, its friction is useful in retaining the wedge in its 
position. 

Law. — The power (acting parallel to the base instead of the in- 
clined surface) counterbalances a weight as many times greater than 
itself as the height of the wedge is contained in the base. When 
applied to the teeth, the wedge increases the diameter of the arc of 
a circle in which the teeth are implanted. It is usually made from 
a fine-grained wood or of India-rubber. It is a direct and positive 
force, and is very eflTective. Teeth with long roots, which are 
set deep in the alveolar process, when the latter is dense and hard, 
are difficult to start with ordinary regulating appliances. In such 



200 IRREGULARITIES OF THE TEETH. 

cases the wedge is of great service. It will readily move one or two 
teeth, and not infrequently three will be influenced by its pressure. 
Wedges made from orange wood are found to be very serviceable, 
as they can be readily reduced in size as the case may require. 
When applied to the teeth they become saturated with saliva, swell, 
and in so doing force the teeth apart. When a rubber wedge is 
used we select one slightly larger than the space between the teeth, 
and by its elasticity the teeth are spread. The rubber wedge per- 
forms its work with greater rapidity, perhaps, but it causes more 
pain than the wooden wedge. Owing to the elasticity of the rubber 
the teeth vibrate with each effort of mastication, whereas they 
would be held firmly by the wooden wedge. 

THE SCKEW. 

The screw, another of the mechanical powers, is also a modifica- 
tion of the inclined plane, and always requires a lever for the pur- 
pose of turning it. It may be used for penetrating wood, like a 
thumb-screw, a gimlet, etc., or it may be used as a moving force, as 
in raising buildings or in the familiar letter-press. In these cases 
it must work in a hollow cylinder with a corresponding thread cut 
inside, which is called the female screw, or nut. When the screw 
is turned in the nut, it will either advance or recede. 

Law. — With the screw, the power produces a pressure as many 
times greater than itself as its circumference is greater than the dis- 
tance between the threads. 

It should be noticed that, unlike the other mechanical powers 
described, the screw works by impulse, each turn producing an 
effect at once, when the motion is ended. This kind of force is of 
great importance to the dentist. It is a positive force, and when 
properly applied, it can always be depended upon. It is a power- 
ful agent in spreading the dental arch, obstinate cases yielding 
readily to the pressure. 

If the deformity be only on one side of the arch, it will be 
necessary to obtain either a point opposite, by uniting three or 
four teeth with bands, and thus giving a strong support, or to in- 
sert a rubber plate and vulcanize the nut into place. When the 
plate is finished, a groove may be cut or a hole drilled to hold 
the screw in place. The screw may be called a universal force, 
as it can be made to force teeth in or out. Where the roots 



PRELIMINARY CONSIDERATIONS. 



201 



Fig. 12^ 



are in a diagonal position in the jaw, or are in close proximity to 
their roots, the screw is very effective. We are indebted to Dr. 
Wra. H Dwinell, of New York, for the introduction of the jack- 
screw as a powerful and direct force in regulating teeth. The fol- 
lowing cuts illustrate those now in the market (Fig. 120). Nos. 1, 
2, 3 are the original jack-screws 
introduced by Dr. Dwinell, and 
are very efficient when combined 
with rubber plates. The screw is 
what is termed in mechanics a 
right-hand thread with a single 
nut. The distal end of the screw 
is made conical that it may be 
directed either in the plate or 
band around the tooth to be 
moved. Holes should never be 
drilled into sound teeth for this purpose. I have invariably been 
successful in encircling the tooth or teeth with a band of gold or 
platinum retained in place by the oxyphosphate of zinc, and for 




Fig. 121. 




the purpose of retaining the band and preventing the accumulation 
of moisture, have usually drilled a hole through the band to guide 
the screw. 

Nos. 4, 5, 6 show Dr. A. McCullom's invention, and are called 



202 IRREGULARITIES OK THE TEETH. 

compound jack-screws. They are made with a right and left thread, 
with nuts to correspond, so that when adjusted they will expand or 
contract if a lever be inserted in the holes drilled through the cen- 
tre of the bar and moved in either direction. The length of the 
bars may differ according to the convenience of the operator. 

Fig. 121 represents a very effective jack-screw invented by Drs. 
Lee and Bennett. It consists of a screw and a split-post nut. The 
plate must be securely fastened in the mouth ; but before its inser- 
tion the post should be vulcanized into it. The proximal end of 
one of the screws has a swivel, which is to be fastened to the tooth 
in order to push it out into line. The other screw has a cross-head 
upon its proximal end, with holes drilled through it for the purpose 
of receiving wire ligatures, which have been passed around the 
tooth to be brought into line. The screw should always be used in 

Fig 122 Combination with a plate or with bands ; otherwise, the 

teeth and gums are liable to be injured. When the bicus- 
pids or molars stand inside of the arch, and a uniform 
pressure is required on both sides of the arch, we may 
prevent the nut from working into the gum by placing 
around the teeth to be moved platinum bands with projectives sol- 
dered to the edge nearest their cervical margins (Fig. 122). 

ELASTIC FOECE. 

Each of the six mechanical forces has its proper place in the art 
of regulating teeth, and when skillfully applied each is an effective 
agent. The application of these forces, however, is limited. In 
looking about for effective powers we find that the force of elastic- 
ity as found in India-rubber and the spring of metals combines all 
that is necessary to render effective either the most rudimentary or 
the most intricate appliance. The simplicity of the application of 
this force makes it very desirable in dentistry. Elastic bands cut 
from French rubber tubing can be universally used, and are appli- 
cable to every case of irregularity of the teeth. There is a power 
in elasticity peculiarly adapted to the correction of irregularities, 
and which cannot be obtained by any of the forces previously men- 
tioned, viz., a constant, equable pressure, which may be either in- 
creased or diminished by the application of larger or smaller bands. 
This constant pressure produces a rapid absorption of the bone 
which opposes the restoration of the tooth to its normal position. 



PRELIMINARY CONSIDERATIONS. 203 

When the rubber bands are applied to the teeth, the point of 
resistance becomes a very important feature. The resistance must 
equal or exceed that of the body to be moved ; otherwise, the 
weaker will be moved by the stronger force. If a tooth upon one 
side be irregular, a tooth, or, if necessary, several teeth, at the 
opposite point must be selected to withstand the pressure of the 
tooth to be moved. This not only requires a thorough knowledge 
of the anatomy of the teeth and jaws, but ability to judge the com- 
parative resistance of each tooth. We once tried to draw by the 
gold band and screw power a right superior cuspid into the space 
made vacant by the loss of a first bicuspid. The point of resist- 
ance was the second bicuspid and the first permanent molar. It 
was found, after turning the nut two or three days, that the bicus- 
pid and molar had been drawn forward half the space instead of 
moving the cuspid into the expected position. 

When the rubber bands are employed in cases requiring much 
force, it is generally a good plan to fit a rubber plate to the teeth 
and jaw, to which arms of rubber or gold are attached in such a 
manner that the teeth may be drawn in or out, as the case requires. 
The plate should be fastened by ligatures to fix teeth, and acts as 
the point of resistance. Rubber bands cut from tubing (or, better, 
from rubber dam, as suggested by Dr. G. V. Black) are attached 
to the arms and carried over the teeth to be moved. Fig. 123 is 
from the model of the teeth of a boy fourteen years of age. The 
lower jaw occludes outside of the upper. A plate with gold band 
attachment (Fig. 1 24) was made to fit the jaw, extending from the 
first bicuspids around the incisors and cuspids, separated from them 
by a distance of a quarter of an inch. The plate was secured to 
the first molars and first bicuspids. Rubber-dam rings w^re fast- 
ened to the band and carried over the incisors and cuspids. The 
teeth were in a short time brought out in place by the attachment 
of rubber rings to the gold band and over the teeth. The result 
is illustrated in Fig. 125. Fig. 126 illustrates a plate made for the 
purpose of drawing in the protruding central incisors of the upper 
jaw. A band of gold is adjusted to the labial surfaces of the teeth, 
to which hooks are soldered and bent over the cutting-edges, to 
prevent the band slipping up to the gum. An elastic band is 
fastened to the centre of the plate and attached to the gold between 
the central incisors. By this means the teeth are readily brought 



204 



IRREGULARITIES OF THE TEETH. 



into their proper positions. When moving teeth or twisting them 
in their sockets by elastic bands, it is desirable to start the teeth 
with wedges of wood or rubber, or with the jack-screw, to produce 
absorption of bone about the roots and make the resisting power 
less complicated when the bands are finally applied. 



Fig. 123. 



Fig. 125. 




Fig. 127 represents the model of the mouth of a woman twenty- 
six years of age. The central incisors diverge from the median 
line, and are also twisted in their sockets. Rubber bands were 
placed about the teeth to draw them together. The pressure re. 
quired was so great that two bands, each one-fourth of an inch 



Fig. 124. 



Fig. 126. 




After Kingsley. 

wide, with a linen ligature tied with a surgeon's knot on the outside 
of the bands, were required. Even with this powerful force it took 
three weeks to bring the teeth together. Having produced absorp- 
tion of the alveolar process, the teeth were easily rotated in their 
sockets in the following manner : 

A band of platinum was accurately fitted to the crown and sol- 
dered. A hook was made by inserting and soldering a pin from an 



PREUMINARY CONSIDERATIONS. 205 

artificial tooth into a hole drilled in the labio-distal angle of the 
band ; this band was fastened upon the tooth with oxyphosphate of 
zinc ; a band of rubber was then attached at one end to the hook, 
and at the other to a bicuspid, the tooth being thus rotated into 
place. Another plan is to dry the tooth, coat it with sandarac 
varnish, and while moist to wind about it a strip, cut from rubber 
dam, three-sixteenths of an inch wide and two inches long, with a 
string tied in its middle, so that the rubber dam doubles upon itself. 
The band should be wound in the same direction in which the tooth 
is to be rotated, and the winding should be continued until the end 
of the rubber reaches the distal edge of the tooth ; the string should 
now be drawn across the mouth and tied to a molar or bicuspid 
tooth. Either of these arrangements is very effective. 

Fig. 127. 




LIGATUEES. 



Ligatures are cords, strings, or wires for binding the teeth while 
regulating, for the attachment of other appliances to the teeth, or 
for holding them securely after they have found their places. Silk, 
linen or Chinese grass ligatures serve a good purpose, but the ordi- 
nary silk twist found in dry-goods stores does the work better than 
any other ligature. When ligatures are used to regulate, they act 
upon the teeth to be moved by attaching them to a fixed point, and 
also by the shrinkage of the fibre when moistened. Care should be 
taken in tying the knot of a ligature to avoid its working up under 
the gum. Various knots can be made for this purpose. Fig. 128 
shows some good ones. Since the introduction of Dr. Magill's band 
for regulating teeth, the ligature has become a very useful adjunct 
for fastening appliances at any point upon the band where a pin has 
been previously soldered to it. 



206 



IRREGULARITIES OF THE TEETH. 



THE ELASTICITY OF METALS. 



The molecules of 




After Farrar. 



metals are held together by a force called 
cohesion. These particles change 
in their relative positions when the 
metal is acted upon by an external 
force. If this force be removed before 
these changes exceed a certain limit, 
the particles return to their previous 
positions. This power of returning to 
original form is called elasticity. This 
elasticity of metals may be utilized in 
regulating teeth with powerful results, 
which are only limited by the amount 
of spring which a metal possesses. 
Metals are classified as perfectly elastic 
and inelastic, which terms imply that 
there are many degrees of elasticity be- 
tween the two extremes. It is now 
claimed that a metal cannot be perfectly 
elastic ; that is, it cannot go back ex- 
actly to its previous form. It is also 
claimed that every body is elastic in a 
degree. Pure gold itself belongs to the 
inelastics ; when alloyed with other 
metals, e. g., platinum, it is a perfectly 
elastic metal. Some members of the 
dental profession have utilized this 
force for regulating wdth great suc- 
cess. 



CHAPTER IV. 

CONSIDERATION OF DIFFERENT METHODS. 

THE PATRICK METHOD. 

The system of regulating devised by Dr. J. R. Patrick, of Belle- 
ville, 111 , is unlike any of its predecessors. It is based upon the 
elasticity or spring of a bow-spring wire of platinized gold, which is 
anchored by suitable bands to teeth selected for this purpose. The 
wire is half round and of a standard size ; the bands for anchorage 
are attached to suitable slides, fitting the wire accurately, so that they 

Fig. 129. 




can be at once adjusted to the teeth selected. The force of the bow- 
spring wire is applied to the teeth which it is desired to move by 
means of wedges, hooks, T-bars and catches, of shapes and sizes as 
desired, which are attached to similar slides, all fitting the bow- 
gpring wire, so that any desired number or forms of appliances can 
be readily adjusted at the same time. 

Figure 129 represents the bar or wire, which is bent so as to con- 
form to the buccal surfaces of the teeth ; and the different attach- 
ments are also shown. In use, the anchor bands are properly ad- 
justed aind retained in position by set-screws parsing through them, 
and provided with a head or button for turning them, as shown. 
The wire rests upon the buccal surfaces of the molars to which it is 

207 



208 IRREGUI.ARITIKS OF THE TEETH. 

attached, and the hooks, wedges or other appliances are brought to 
the positions desired. 

Any tendency of the anchor bands to change their position upon 
the teeth may be obviated by lining them before adjustment with 
thin oxyphosphate of zinc. If the bar incline to slip upward 
toward the gingival margin, this may be obviated by an attachment 
in the shape of a small hook resting upon one of the teeth. 

The apparatus acts as a lever, the power being the elasticity of 
the bow-string, the fulcrum the teeth used for anchorage, and the 
resistance the tooth or teeth to be moved. Kubber bands may also 
be used as auxiliaries. 

This appliance is ingenious and possesses many advantages. It 
is claimed by the inventor that any form of irregularity can be 
successfully treated with it. Only one band is needed, and no im- 
pression of the mouth is required ; being composed entirely of 
incorruptible metal, it is easily and thoroughly cleansed, and with- 
out removal from the mouth. It can also be adjusted or tightened 
at any time without removal. It can be applied to either jaw with 
equal facility. 

The principal objection urged against this appliance is that the 
teeth used as fulcrums or attachments are sometimes not sufficiently 
firm to resist the pressure they are required to sustain, and in that 
case will move before the tooth which is being operated upon. This 
could probably be obviated by attaching to more teeth. 

The construction must, of necessity, be accurate, and if made by 
the dentist, requires great nicety of workmanship. But all diffi- 
culties of this nature are banished by the fact that it can be ob- 
tained at the dental depots. 

THE FAERAK METHOD. 

Of the distinctive systems of apparatus for regulating the teeth, 
those devised by Dr. J. N. Farrar, of New York, were among the 
first to be presented to the profession. They were introduced by 
him about 1873. The principle upon which they operate is pecu- 
liar to the system, which is called by him "The Positive." In all 
(or most) methods employed previously, the endeavor was to bring 
to bear upon the tooth or teeth to be moved a force that should be, 
so far as possible, continuous. Rubber bands, springs, etc., are ex- 
amples of this continuous force, which it is the endeavor to con- 



CONSIDERATION OF DIFFERENT METHODS. 



209 



tinue, in greater or less degree, from the beginning to the end of the 
operation. 

Dr. Farrar's system is peculiar in this, that he uses, when he can, 
the screw for power, which he considers to be the only force capable 
of being accurately applied with a definite and positive result. 
His theory is that a tooth should be moved a certain distance, as 
far as it is safe or proper, at one operation, and then retained im- 
movable in that position until another operation. By this means 
he claims that the tissues in front of the advancing tooth are com- 
pressed, and kept compressed, to such a degree that absorption 
takes place readily and without inflammation, thus making place 

Fig. 130. 




for the tooth being moved, while, at the same time, a deposition of 
tissue takes place behind the tooth, tending to retain it in its new 
position. This, then, is the principle of the Farrar method : a 
positive movement to a known and definite extent, the tooth being 
retained by the appliance in the new position, and a period of per- 
fect rest allowed to intervene before more force is applied. 

The apparatus by which the results are accomplished is con- 
structed of 18-carat gold. An illustration of one appliance is 
shown in Fig. 130. 

In most of his appliances is a screw, upon which the threads are 
cut — one hundred and forty to an inch. The end of the screw is 
fitted to be turned with a watch key (Fig. 131), one-half a turn 
14 



210 IRREGULARITIES OF THE TEETH. 

twice a day will move the tooth rio of an inch a day, which 
rate of progress Dr. Farrar finds, by experiment, to be about the 
maximum rapidity consistent with safety ; and he claims that this 
will produce only a slight uneasiness or sense of tightness, and no 
pain. He also claims that patients may be easily instructed to 

Fig. 131. 




turn the screw themselves, and to regulate the pressure by the 
sense of tightness, thus saving many visits to the office and the 
time of the operator. 

THE BYENES METHOD, 

Dr. B. S. Byrnes, of Memphis, practices a method of regulating 
which is worthy of notice."^ He uses thin gold bands, 20 or 22 
carats fine, the motive power being the spring or elastic force of the 
bands. No plates are used, the anchorage being obtained upon 
such of the teeth as are suitable. " The fixed points having been 
determined, the teeth to be regulated are connected to them by 
means of a thin gold band. This is so manipulated as to form a 
spring or series of springs, so adjusted as to bear most powerfully 
on the misplaced tooth or teeth. For instance, in the case of a 
misplaced incisor, to be drawn inward, a continuous band embrac- 
ing the first molars on each side is fitted around the outside of the 
arch. With a dull-pointed instrument like a burnisher, the ribbon 
is then pressed into the interstices of the teeth over which it passes, 
thus forming it into a series of small springs. The incisor, being 
the most prominent point, will naturally be most affected by the 
pressure exerted by the springs, and in a short time it will be found 
to have moved away from the band, so that it is no longer affected 
by the tension of the springs. The apparatus is then removed, the 
ribbon is annealed, straightened, and a small piece cut out of it ; 
the ends are soldered and it is replaced, and the band formed into 
a spring, as before." 

This method is stated to be equally applicable to both simple and 

* Dental Cosmos,' May, 1886. 



CONSIDERATION OF DIFFERENT METHODS. 



211 



complex conditions. Sometimes the spring of the band may be 
advantageously supplemented by other aids, as the insertion of a 
rubber wedge at particular points. The fixture in all cases should 
be perfectly tight-fitting on the teeth. It may be applied gradu- 
ally, so that the teeth yield, and the appliance will then more 
readily go into its place. When the rubber wedge is to be used, it 
should be inserted behind the band opposite to one of the inter- 
stices ; then being stretched, it can be worked to the desired spot? 
when the ends should be clipped off. 

Fig. 132 illustrates a case treated and described by Dr. Byrnes. 
The patient was a young lady of eighteen years, who had lost the 



Fig. 132. 




right superior central at the age of eleven. A vulcanite plate had 
been worn for three and a half years. The remaining upper an- 
terior teeth had been forced outward until they stood at an angle of 
forty-five degrees when first seen. The lower incisors stood inside 
the arch, and the chin was consequently wrinkled and upturned. 
The lips wore a constant pout, the mouth being what is termed 
peaked, the molars being the only teeth that occluded properly. 

In treating this case it was the object, — 1st, to correct the " peak- 
edness " by producing a broader and more oval arch ; 2d, the re- 
duction of the projecting teeth ; 3d, the improvement of the articu- 
lation ; and 4th, the closure of the space caused by the loss of the 
central. The last was undertaken first. The heavy band (Fig. 
133) was used to force the cutting edges of the right central and 
left lateral together. A very thin narrow gold band was then fitted 
to embrace the necks of these teeth, and a wedge of wood was in- 



212 



IRRBGUI.ARITIES OF THE TEETH. 



serted on the side next the cutting edges, causing the teeth to move 
vertically toward each other. Another band (Fig. 134) was then 
constructed to move the incisors backward, and was placed in posi- 
tion without removing the first. It embraced the cuspids and bi- 
cuspids on each side ; the connecting band was pressed into the in- 
terstices, and rubber wedges inserted. The effect of this was not 



Fig. 133. 



Fig. 134. 




only to cause backward pressure upon the incisors, but an outward 
pressure on the cuspids and bicuspids. At the end of three weeks 
the work was practically accomplished, and the fixture was replaced 
by that shown in Fig. 135, which completed the movement of the 
teeth, and acted as a retaining piece. The small hook counteracted 
the tendency to slip up toward the gum. 

Fig. 135. 




The regulation of the lower teeth was begun soon after that of 
the upper jaw was completed, and was carried through in about 
three weeks. A band, shown in Fig. 136, was used, clasping the 
first molars, passing around the bicuspids and behind the incisors. 
A wooden wedge was placed between the incisors and the band, and 
springs formed by pressing the latter into the interstices between 
the cuspids and bicuspids. In two weeks this apparatus was re- 



CONSIDERATION OF DIFFERENT METHODS. 



213 



placed by that shown in Fig. 137. A little block of rubber under 
each of the rings, which rested upon the cuspids, completed the 
work in a week. The rings being pressed back to preserve the 



Fig. 136. 



Fig. 337. 




Fig. 138. 




ground already gained, the piece was worn as a retaining plate. 
The final result is shown in Fig. 138. 

Fig. 139 illustrates the teeth of a lady aged twenty-eight. The 
lower cuspids closed in front of the upper ; the dentes sapientes were 



214 



IRREGULARITIES OF THE TEETH. 



eruptiDg into a crowded arch, and pushing the lower cuspids still 
further forward. The first bicuspids were extracted to make room, 
and the cuspids were moved backward by means of a band, shown 
in Fig. 140, which embraced the first molar and cuspid. The 



Fig. 141. 




molars were capped to prevent occlusion, but the age of the patient 
preventing rapid movement, the bands were cut and tightened only 
twice a week. In ten weeks the work was completed — Fig. 141 
showing the appearance at the conclusion of the treatment. 



Fig. 142. 




Fig. 142 shows the upper jaw of a lady aged twenty-two, w^ho 
fell at the age of ten years, striking the superior teeth in such a 
way as to knock out the right lateral and dislocate the other incisors, 
the left central remaining at an angle of thirty-five degrees after 
its attachment was again renewed. The incisors were separated 



CONSIDERATION OF DIFFERENT METHODS. 



215 



from each other, and the deformity was much more marked than 
shown by the cut. 

Fig. 143 shows the appliance in position used by Dr. Byrnes 
in this case, by which the regulation was completed in eight 



Fig, 143. 




sittings. The connecting band was crimped as shown, thus 
converting it into a series of springs. Fig. 144 was used in a 
case in which the right central overlapped the lateral. The 



Fig. 144. 




springs were adjusted so as to turn the tooth, the work being 
accomplished in four days, after which it was retained by a simple 
band, with wings resting on the left central and under the right 
lateral. 



THE HEADEIDGE-COFFIN'S METHOD OF PKACTICE. 

Dr. Walter H. Coffin, of England, read a paper before Section 
XII. of the International Medical Congress, held at London, in 
August, 1881, upon '* A Generalized Treatment of Irregularities " 



216 



IRREGULARITIES OF THE TEETH. 



Upon that occasion he described a system of cleft-plate devices. 
The principle upon which this system of regulating is based is 
different from most others. It was not new nor entirely their own. 
Since it became known in this country it has come into consid- 
erable use, and is popularly known as the " Split Plate " Method. 

The principle upon which this method acts is by the construc- 
tion and adaptation of a vulcanite plate, not only covering the hard 
palate, but capping the posterior teeth ; the plate, after vulcanizing 
and finishing, is to be split into halves. These halves are con- 
nected by a piece of wire bent into the shape of the letter W (Fig. 
145), having the ends flattened and imbedded in the vulcanite 
plate. This wire, or spring, being suitably adapted to the cast, and 
bent with the proper shape while cold, is pressed into the wax 

Fig. 145. Fig. 146. 




model upon the cast until the proper position is secured. To pre- 
vent its displacement while packing, bits of binding-wire may be 
twisted around it at various points, which will hold firmly in the 
plaster. A piece of heavy tin-foil covering the wax model on the 
lingual surface will bring out the rubber with a polished surface 
under the wire. The piece, having been vulcanized, is split length- 
wise with a fine saw (Fig. 146). The plate is now introduced and 
properly fitted. To secure acccurate adaptation to the teeth, a per- 
fect impression and a perfect model are necessary. Dr. Coffin 
recommends gutta-percha or balleta gum (modeling compound). 

The plate, being properly adjusted in the mouth, is worn without 
any tension for a day or two — until the patient has become accus- 
tomed to its presence. The two halves are then separated by being 
stretched apart, by which means the piano-wire is converted into a 
spring of great power and constant tension. It is claimed that any 
desired direction may be given to the force, and the pressure thus 



CONSIDERATION OF DIFFERENT METHODS. 217 

brought to bear where it is most needed, but by many dentists this 
is not easy. 

The prima' y effect of this arrangement is of course, to expand the 
arch laterally, thus affording room for the rotation or removal of the 
irregular teeth. In a large majority of cases such an expansion is 
either absolutely essential or highly desirable, and by this appliance 
this is claimed to be easy to do. The inventors even claim that, para- 
doxical though it may seem, it is less painful and troublesome to 
secure in this way ample spaces between all the front teeth at once 
than to wedge two of them apart in the ordinary way, with the ad- 
vantage of easily maintaining their separation. 

Fig. 147. 




This appliance, as will be readily seen, is designed for an altered 
shape or outline of the dental arch ; where this is not needed the 
power of the spring, or of a suitable spring properly inserted, may 
be brought to bear upon any tooth which it is desired to operate 
upon, so as to produce rotation or movement in any direction. In 
this case the plate is not split, but wire is anchored into it in a suit- 
able position, its end protruding to bear upon the tooth it is desired 
to move. Wires can be inserted so as to operate on one or two 
teeth at the same time. (Fig. 146.) 

The same principle may also be applied to the regulation of 
teeth in the lower jaw. In this case the plate (Fig. 147) is made 
in a horseshoe form, and the wires lie along its lingual aspect 
in a simple U-shape or semicircle, the plate being divided at the 
median line. 

By stretching the spring more and more as the case progresses, 
an expansion to a very considerable extent may be effected, and 



218 IRREGULARITIES OF THE TEETH. 

so easily that caution must be observed not to exceed the in- 
tended results. 

PIANO-WIKE. 

Piano-wire is manufactured in Germany, England and America. 
It is made of the best steel, drawn through a draw-plate to the 
required size. The polish and temper are given during this pro- 
cess. The wire must be e:^tremely pliable and strong to endure 
the tension which it undergoes during the tuning process of a 
piano. It must also be perfect in construction, as any flaw in 
the wire would cause it to snap when being manipulated. It has 
advantages over any other wire for dental purposes. It is inex- 
pensive, has greater elasticity than other wires, and can be more 
easily adapted to a variety of cases. It can be bent in any way 
necessary to obtain the greatest amount of force, and can be ap- 
plied to any place in the mouth, on account of its small size 
and weight. Sizes 18, 19, 20 are better suited to the majority 
of irregularities, the strength of the wire to perform a given 
operation depending upon the age and constitution of the indi- 
vidual and the character of the irregularity. In youth or in 
delicate organizations, No, 20 is the size best adapted to regu- 
late; the sizes should decrease to oS'o. 17 as the years advance, 
or as the stubbornness of the irregularity demands. The selection 
of the wire, and adapting it to each special case so as to obtain 
the best results and avoid producing inflammation, will require 
the nicest discrimination. 

THE AUTHOR'S METHOD— THE COIL SPRING. 
In order to obtain the best results, the elasticity of the wire 
was increased by coiling it from one to three times around a 
mandril. The author has placed his coil springs at the dental 
depots for the benefit of those who cannot take the time to make 
their own springs. The mandril is driven into the bench, and 
with the right hand the wire is coiled about it as many times 
as required, the short end being held firmly by the left hand. 
The coil ends directly at the starting-point, and gives thereby 
the greatest elasticity and length of arms. When necessary, the 
long end of the wire can be bent with square-nose pliers to make it 
on the same plane with the other arm. Fig. 148 shows the coil 
spring. 



CONSIDERATION OF DIFFERKNT METHODS. 



219 



The coil of the spring works on the same principle as the 
mainspring of an American watch, which between two points 
measures a uniform period of time. The extremities of the arms 
of the spring travel over a given space with like uniformity, 
which gives a mild, uniform pressure to the jaws and teeth. The 
arms may be bent or cut at any length to suit the case in hand. 
They may be used in connection with a rubber plate, or with bands 
of gold or platinum fastened to the teeth with oxyphosphate of zinc. 




With holes properly drilled in the plate or bands, and the arms 
fitted into them, the spring will stay in position. When the spring 
is used without a plate, it will be well to fasten the wire in some of 
the teeth to prevent its being swallowed. 



Fig. 149. 




The following histories will illustrate some of the cases in prac- 
tice : 

The following models of the mouth of a girl sixteen years of age 
were presented to the author, who assisted, by Dr. J. F. Austin, of 
Chicago. The right cuspid had encroached upon the lateral incisor 



220 



IRREGULARITIES OF THE TEETH. 



to such an extent as to twist and force it out of position, leaving 
only about one-half of the space necessary to rotate the tooth into 
place. A plate was made to fit the mouth and teeth, and a coil- 
spring inserted, with arms meeting the cuspid and central incisor. 
The spring was secured to the plate by a pin driven into the plate 
(Fig. 149). By the lateral pressure of the spring the teeth were 



Fig. 150. 




pushed apart, making space for the teeth to be rotated into place. 
Fig. 150 shows the tooth secured in position by the Magill retainer. 

SPKEADING THE DENTAL AECH. 

On an exact plaster model of the case to be regulated a thin, 
narrow vulcanite plate is formed, with a short vertical post fixed, 
either before vulcanizing or afterward by drilling centrally in the 
plate on the median line. Grooves or slots are, with a wheel bur, 
cut in the sides of the plate to receive the ends of the spring and 
prevent its displacement after the coil has been placed on the post. 
Fig. 151 represents such an appliance in position on a plaster cast 
of the inferior maxilla of a boy aged twelve years, and it will thus 
be seen that the movements of the tongue would not be, as in prac- 
tice they were not, seriously restricted. The tension of the spring 
is changed by simply bending outward or inward its arms, and in 
many cases the apparatus may be inserted or removed with great 
facility, and its action be so continued and controlled that the re- 
quired expansion may be obtained and maintained by the use of 



CONSIDERATION OF DIFI^KRRNT METHODS. 



221 



but one plate. This plate, with spring attached, was removed by 
the boy twice a day, and the teeth and plate cleaned. 

In spreading the dental arch the majority of cases require the 
greatest pressure on the anterior teeth, and an appliance that can 



Fig. 151. 




be placed inside the arch will exert the greatest influence. The 
force is equally distributed on both sides of the mouth, and if con- 
stant the work will be accomplished rapidly, without inconvenience 
to the patient. Such an appliance is here illustrated (Fig. 152). It 

Fig. 152. 




is used in the mouth of a young girl fourteen years of age. A 
plate is made to fit the teeth and alveolar process, and cut away so 
that the anterior parts extend far enough forward to inclose the 
teeth to be moved. A piece of wire is bent into either of the forms 



222 



IRREGULARITIES OF THE TEETH. 



shown in Fig. 153, wherein a is the coil and fixed point, and h h 
movable arms extending from a, and also fixed points , c c, movable 
arms extending from h h. 

Grooves are cut into the anterior and posterior parts of the 
plate to correspond with and receive the points h h and c c. Holes 
are drilled at these points, and the wires tied to the rubber plates. 
In order that the anterior teeth may be moved with the greatest 
force, the arms are so adjusted that the greatest pressure is exerted 
on the anterior parts of the plates. This appliance is readily re- 
moved for cleansing, and returned to place by the patient. 

Another appliance for spreading the dental arch that has been 
successfully used by the author is illustrated in Fig. 154 ; it consists 



Fig. 154. 



Fig. 155. 




of a rubber plate made to fit the teeth and jaw. The plate is then 
sawed lengthwise — commencing at a point anterior to the teeth to 
be moved ; a hole is drilled at the point where the slot stops, to 
prevent the arms breaking. At the extreme end holes are drilled 
to receive the spring. To adjust the plate press the arms together 
and drop the plate into place. Fig. 155 shows the plate out of the 
mouth. This can be removed and inserted ad libitum by the 
patient. 

A form of dental irregularity very difficult to correct is found 
when the cuspids are situated near or in contact with the centrals, 
while the laterals stand inside of the arch, and when the jaws 
are closed pass behind the central incisors. If these laterals are in 
near relations to each other, it is by ordinary means well-nigh 



CONSIDERATION OF DIFFERENT METHODS. 223 

impossible to interact upon them with sufficient pressure to force 
them apart ; the space being quite too short to admit a jack-screw. 

Fig. 156 represents such a condition. The cut is made from the 
cast of a case in practice, the patient being a young woman 
eighteen years of age, who came under my care in 1883. The 
superior laterals were then only one fourth of an inch apart, and 
closed behind the inferior incisors. There were but small spaces 
between the superior centrals and cuspids. 

Thin platinum collars were made to fit the laterals, on which, 
after drilling a hole in the side of each collar, they were firmly 
fixed with oxyphosphate of zinc. A spring was bent into the form 
shown by Fig. 157, the ends of the arms being turned at a sharp 
angle and cut short, as seen in the figure. 

The spring was then put in place, the arm ends entering the 

Fig. 156. Fig. 157. 





holes in the collars, and the curved arms found to be so closely 
conformed to the surface of the gums and palatine parts that the 
fixture was no obstruction to occlusion, and yet could be easily 
sprung out of position for cleansing purposes or for increasing the 
expansive power of the spring, by simply widening the lateral 
spread of the arms. Fig. 156 shows the progress made in four 
weeks' treatment. When the laterals had been moved past the 
sides of the centrals, they were by other means forced outward into 
line. 

EEGULATING INDIVIDUAL TEETH. 

To force out central and lateral incisors, I have found the fol- 
lowing methods useful : Around the tooth to be moved, and around 
the molars, as nearly opposite the direction the incisor is to travel 
as possible, fit platinum collars. Solder cups upon the collars 
directly opposite and in line. Make a spring of piano-wire (Fig. 



224 



IRREGUI.ARITIES OF THE TEETH. 



158), and spring it into the cups soldered upon the collars. In 
Fig. 159 the appliance is seen in place. 

Another method is to make a plate to fit the teeth, thickening it 
nearly to the cutting edge of the tooth to be moved, and drilling a 



Fig. 158. 



Fig. 169. 





hole through the thickened part. Directly opposite, at some con- 
venient point on the back part of the plate, drill another hole just 
deep enough to hold the spring in place (Fig. 160). If the hole in 
the thickened part be drilled in the proper place, the end of the 




spring will hit the tooth midway between its cutting-edge and the 
margin of the gum. The spring is very efiective. The pressure is 
constant, and the spring is readily removed for adjustment or for 
any other purpose. 



CONSIDERATION OF DIFFERENT METHODS. 



225 



We frequently find a single tooth situated inside the dental arch, 
and have trouble in contriving an apparatus suited to the correc- 
tion of such an irregularity. 

The illustrations represent some simple appliances that have been 
thoroughly tested and found satisfactory, in that they do the work 
effectively, are easy of adjustment and removal, and may be readily 
cleansed. 

Fig. 161 illustrates a second inferior bicuspid of the right side, 
having a lingual presentation equal to one-half the thickness of the 

Fig. IGl. 




tooth inside of its normal position. The cut also shows teeth in 
other malpositions ; but for our present purpose these are not con- 
sidered. 

For this case a thin, narrow, close-fitting vulcanite plate was 
made, and a hole was drilled through the middle of the plate oppo- 
site the centre of the tooth to be moved. In the other side another 
hole was drilled, but not quite through the plate. A suitable 
spring (Fig. 162) was then made of piano wire, having a single 





coil, A, and the ends of its arms bent at about a right angle. One 
of these ends, C, was cut short to enter the corresponding hole in 
the plate, and the other end, B, left long enough to go through the 
plate and impinge on the lingual surface of the bicuspid, leaving a 
full eighth of an inch between that arm of the spring and the 



plate, as is clearly shown by Fig. 161. 
15 



Fig. 1 63 shows both arms, 



226 IRREGULARITIES OF THE TEETH. 

B B, of the same length, to pass through the plate and impinge on 
the lingual surfaces of teeth upon opposite sides. 

Fig. 164 shows an appliance for pulling out the central incisors. 
A plate is made to fit the jaw and teeth, and into it were vulcan- 
ized two of the Talbot springs at the lateral incisor region. The 
wire arms were turned into loops at the extremities to secure a 

Fig. 164. 




ligature. When the plate was adjusted, the arms were bent hori- 
zontally, and brought in close proximity to the labial surfaces of 
the centrals incisors and securely tied. By this means constant 
pressure was applied, and the teeth were carried outside of the 
inferior incisors. 



CHAPTER y. 

TEEATMENT OF SPECIAL FOKMS OF IRREGULAEITIES. 



ROTATING TEETH IN THEIR SOCKETS. 

The Farrar Method. 

Dr. Farrar has devised for this purpose several modifications of 
devices belonging to his "positive system," one of which is illus- 
trated in the following cuts : . 

Fig. 165. Fig. 167. 



=£)' 

ff^ 




b' 





Fig?. 165 and 166 represent screw-wrenches made of 18-carat 
gold, with the exception of the screw in Fig. 166, which may be 
made of brass or steel, as desired. If the form represented in Fig. 
165 be used, it is adjusted on the tooth, and the thin gold of which 
the band is composed is made to hug it by tightening the nut, B, 
and the end of the bar, JP, resting firmly against the adjacent tooth ; 
tightening the nut once or twice a day causes the tooth to rotate. 
If the box-wrench (Fig. 166) be used, the arm acts as a lever, to 
which is attached a band of rubber, and ligature attached to a firm 
tooth, as shown in Fig. 167. Or, both forms may be used, as in 
Fig. 168, the power being obtained by a screw rotating in a swivel, 
K, attached to a distant tooth. 



228 



IRREGULARITIES OF THE TEETH. 



Figs. 169 and 170 show another form of apparatus, so simple and 
so plainly shown by the cuts as to require little description. The 

Fig, 168. Fig. 171. Fig. 172. 







g/ 


nnC^J^D 


»^^e> 





Fig. 173. 




Fig. 170. 




strip of plate resting on the palatal surfaces of the adjoining teeth 
serves as a fulcrum, and the tooth operated on is rapidly drawn 



TREATMENT OF SPECIAL FORMS. 229 

into line and rotated. Fig. 169 represents an upper case treated 
by Dr. Farrar, and, as he states, the patient, about thirty years of 
age, manipulated the apparatus himself, reporting only once during 
the week that the operation was in progress. 

Fig. 171 illustrates a right-angle key or wrench, with bevel pin- 
ions similar to the right-angle engine attachments which Dr. Far- 
rar uses for turning nuts in localities such as that shown in Fig. 
169, or in other localities where it is difficult to use the ordinary 
wrenches. 

Dr. Farrar's " triplex system " is also adapted to the treatment 
of either of these varieties of irregularity, as illustrated in Fig. 
172. " The bearings of the bands upon the different points of the 
teeth and the directions of their movement are indicated by the 
arrows, while the details of construction are shown in the figure, 
and the device is made as follows : A stiff strip of plate, T, is bent 
on a form to loosely fit the necks of the teeth at certain points 
under the free margin of the gums, and prevent the plate from 
slipping from the teeth ; and the ends of the plate are so shaped as 
to bear firmly on the distal corners of both teeth. These bearings 
may be changed by properly bending the ends of the plate as the 
operation advances. The bridge, C, carries two rollers, W W, be- 
tween which the thin ribbon loop, L, passes, and is caught by its 
fold on a wire attachment to the middle of bar, T, as shown in 
position on the tooth. The screw, S, is swiveled in the JSC end of 
the metallic ribbon loop, and screws into the threaded end, with the 
effect of separating the ends of the loop, which thus moves the 
bridge toward the bar and rotates both incisors. 

" Other modifications of this device may be adapted to different 
presentations of this class of cases, the main thing to be kept in 
view being the points of bearing of the bridge, C, and the bar, T ; 
for while the apparatus will work well when the teeth have small 
necks, it is difficult of retention upon tapering teeth. 

" In some cases a firmer hold on the teeth may be obtained by a 
pair of narrow loops, the folds of which pass on either side of the 
bar, around the ends of a pin passing through and projecting 
from the middle of the bar, as shown in Fig. 173 The bar thus 
made and connected is easily detached for the purpose of bending 
its arms to obtain rotative bearings. A key for turning the screw 
may be readily made from an excavator, shaped as shown at K, 
Fig. 173." 



230 IRRiCGULARITIES OF THE TEETH. 

THE GUILFOKD METHOD. 

Dr. S. H. Guilford has devised a little fixture for correcting 
malpositions of the central incisors, shown in Figs. 174 and 175. 
According to his description, it is constructed as follows : A piece 
of gold backing one-eighth of an inch wide and sufficiently long to 
extend along and a trifle beyond the palatal surfaces of the cen- 
trals, is bent to conform as closely as possible to their lingual sur- 
faces, and forward so as to slightly clasp the disto-palatal angles, 
as shown at Fig. 176. To this are soldered two strips cut from 

Fig. 174. Fig. 175. Fig. 176. 



plate-scrap, a little narrower than the first piece, and bent in the 
form of h and c (Fig. 176), respectively, which are sufficiently 
long to extend slightly over the anterior and posterior surfaces of 
the teeth. After being properly shaped to fit the model, their 
backs are soldered together and to the part, as 
shown in Fig. 177. The part h c, which passes be- 
tween the teeth, is reduced sufficiently with a file, or 
the teeth may be separated by wedging, to allow the 
insertion of the fixture. The labial part should 
rest against the teeth just at or slightly above the most prominent 
part of the convexity, while the lingual portion should be near the 
gum, but not quite touching it. The slightly-curved ends will 
catch just above the little nodule usually found on the disto-palatal 
angle near the gum. Thus secured, it cannot be easily displaced. 
Bend the long palatal arms slightly toward the short labial ones 
daily, and spring them into position on the teeth. The elasticity 
of the gold, stiffened by the solder, will do the work. " By this 
means," says Dr. Guilford, " the use of all rubber or silk ligatures, 
so irritating to the gum and so painful in application, is dispensed 
with."' Fig. 174 illustrates a case treated by Dr. Guilford with 
this appliance, the cure being complete after a treatment of ten 
days, the patient having been seen every day. The general form 
of the appliance is also equally useful in correcting teeth in the 



TREATMENT OF SPECIAI. FORMS. 231 

reverse position, shown in Fig. 175. In this case the construction 
is reversed, so that the long arm or band may rest on the labial 
and the short one on the palatal surfaces, and so bent as to throw 
the distal angles inward. 

The same appliance, slightly modified, he says, is also useful for 
rotating a single incisor where its mate is already in position. In 
this case the end of the appliance is fitted nicely to the tooth in po- 
sition, while the other half is so shaped as to give the desired pres- 
sure on the tooth to be rotated. 

THE AUTHOE'S METHODS. 

In June, 1884, the following treatment was begun by me for 
rotating the central incisor of a patient. A platinum band was 
made to fit the tooth, and a tube of the same material was soldered 
lengthwise with the band (Fig. 178). The band was secured to the 
tooth with the oxyphosphate of zinc, a piece of piano-wire being 
passed into the tube and allowed to extend to the left central in- 
cisor (Fig. 179). The wire was bent every day, and the tooth thus 

Fig. 178. Fig. 179.' 




rotated into place. When practicable, we should solder a flat tube 
to the band for the purpose of holding a flat lever, which would 
prevent the rotation of the arms. 

For rotating a tooth the most eflScient contrivance is the combined 
lever and collar, fitting and fixed upon the tooth by cement. (Fig. 
180.) The soldering of a flattened tube across the face of the collar 
affords a means for the insertion and removal of the lever at will. 

I prefer a lever made of a piece of thin piano-wire. No. 27, U. S. 
gauge, one end of which is folded upon itself for about a quarter of 
an inch, and the wire then coiled once or twice close to the folded 
end (see illustration). The other end is bent to hook around a mo- 
lar or other posterior tooth. The illustration shows such a tubed 
collar and wire lever separately, and also in place on the tooth 
which is to be rotated. It is obvious that the lever can be removed 



232 



IRREGULARITIES OF THE TEETH. 



or applied without detaching the cemented collar. lu operation, 
the compound lever effects a complex movement of the tooth which 
is being rotated by the lever as a whole, and is at the same time 
thrown outward by the hinge-like action of the short lever turning 
on the coil as on an axis — the result being the proper alignment of 
the tooth, if the spring of the coil and the elasticity of the lever are 
so judiciously combined as to be adapted to the requirements of the 
case in hand. 

Fig. 180. 




The other central incisor could likewise be simultaneously rotated, 
and, after both teeth had been brought into position, a folded wire 
bar through both tubes would retain them in place so long as might 
be deemed desirable. 



MOVING CEOWNS AND BOOTS, 

In most of the operations for regulating teeth, the apices of the 
roots are in a position either normal ar approximating to it in such 
a degree as not to require moying. But in some cases it becomes 
necessary to move the whole root. For this purpose, although the 
power may be the same, yet it must be made to act in a different 
manner. 

In ordinary moving of teeth, the power is at one end, the resist- 
ance at the other, while the fulcrum is in the middle of the tooth to 



TREATMENT OF SPECIAL FORMS. 



233 



be removed. Dr. Farrar illustrates in Fig. 181, where Pis the 
power, F the fulcrum, and S the resistance. The power being con- 
tinued, the teeth are drawn in the direction indicated by the arrows, 
U. The first effect of this movement, so far as the roots are con- 
cerned, will be to cause them to impinge against the septum B, at 
the point F^ and also against the socket wall at the point S. They 



Fig. 181. 



S^'f^. 





will also separate from the s(5ckets at the points A and C, as indi- 
cated by the arrows. If the force be continued in this direction 
until the points touch, as in Fig. 182, the lever is changed into one 
of another variety, in which the power is applied between the ful- 



FiG. 183. 



Fig. 184. 





crum and the resistance (X, Fig. 182). Thus the same power from 
the same apparatus acts in exactly the opposite manner, causing the 
roots to approach each other throughout their length (the fulcrum 
being at 0, Fig. 183), and leave the socket walls in the same man- 
ner. Fig. 184 shows the completion of the operation. 

The appliance used by Dr. Farrar in one such operation is shown 



234 IRREGULARITIES OF THE TEETH. 

in Figs. 185 and 186. "It is made up of two parts — a clamp band 
to draw the teeth together, and a lock portion to hold stationary the 
cutting edges of the teeth ; but while the teeth are being drawn to- 
gether, only the band portion need be used. On each extremity of 
a band made of light and strong rolled wire is soldered a nut, one 
of them being a screw nut. Through these nuts passes a little gold 
screw, having a head fitted to a watch-key. The main point to 
hold in view in constructing this clamp portion is to insure a close 
bearing at the gum border, to prevent it from slipping off the teeth. 
The lock portion, for preventing the overlapping of the crowns 
when the force is continued after the teeth have been brought in 
contact, is a simple device, easiest made by bending a small piece of 
plate about one-quarter of an inch square, or a little larger, trough- 

FiG. 185. Fig. 186. 





like, so as to fit the edges of the teeth ; to this is soldered at right 
angles another piece of plate extending far up between the teeth 
nearly to the gum ; on the upper end of this is soldered, trans- 
versely, about one-eighth of an inch of small tubing (smooth bore), 
through which passes the bolt of the clamp band and from which it 
is loosely suspended. This part (the trough portion) may be con- 
structed skeleton-like, as shown by Fig. 185, and is more easily kept 
clean. The clamp is first applied, the force being intermittingly 
applied two or more times a day, or every time the band loosens by 
the movement of the teeth ; but this should never be powerful 
enough to cause pain. After the teeth are brought in contact, or 
nearly so, the trough portion is added, and the force of the clamp 
band continued until the roots are [brought into the desired po- 
sition. 



TREATMENT OF SPECIAL FORMS. 235 

COMPULSORY ERUPTION OF THE TEETH. 
The Matteson Method. 

Occasionally a single impacted tooth in the jaw does not work 
its way down sufficiently to occlude with its opposite tooth, or the 
incisors do not meet when the jaws are closed. Such teeth are to be 
treated so as to make them as nature intended. Dr. A. E. Matte- 
son, of Chicago, has been successful in using the following 
methods : A rubber plate was made to cover the roof of the mouth 
and to fit the necks of the teeth closely, a French clock spring 
being adjusted with one end riveted into the central posterior part 
of the plate (Fig. 187) ; when the spring was inserted and forced 
up against the plate, the distal end of the spring touched the necks 
of the teeth to be drawn out ; ligatures were then fastened to the 

Fig. 187. Fig. 188. 





necks of the teeth, and the spring carried up to the plate and fas- 
tened to the teeth. If the spring be sufficiently pow -rful, from two 
to four teeth may be operated upon at one time. 

The spring being movable upon the rivet in the plate, one tooth 
at a time can be erupted, and then the point of the spring may be 
turned to the next tooth. 

Fig. 188 shows a similar appliance for erupting the teeth on the 
lower jaw. Erupting teeth is unlike any of the other regulating 
operations, as no pressure to produce absorption is required. 

When the lateral pressure has been removed, the mildest force is 
sufficient to draw a tooth out of the process, as the roots are conical 
and the pressure is directed away from the process instead of 
against it. 



236 



IRREGULARITIES OF THE TEETH. 



Fig. 189. 




The Author's Method. 

The author has been successful in erupting teeth by the follow- 
ing method : Fig. 189 illustrates the right superior lateral arch of 
a boy eighteen years of age. He has been a patient of mine from 
the first. At about the tenth year I was able to indicate in outline 
the crown and root of the cuspid, and noticed the marked obliquity 
of its position. The posterior column was crowding the bicuspids 
forward so that they eventually filled the space allotted to the cus- 
pid. The teeth in the left superior lateral arch came into position 
in the natural order, and that arch was nearly normal. In the 

treatment of this case I waited 
until the point of the cuspid 
made its appearance, when I 
^%m.M^M^i-/'A extracted the first bicuspid. 
Platinum bands were fitted 
to the second bicuspid and 
lateral incisor, and these were 
connected with a bar of plati- 
num extending to and impinging upon the central incisor. A flat 
tube was then soldered to the bar for the purpose of securing a 
coiled spring, made of the smallest size piano-wire, the arms being 
cut to about the same length. One arm was doubled upon itself 
and so adjusted that when it was passed into the flat tube the suit- 
ably bent end of the other arm would reach forward and catch 
upon the point of the cuspid. By this means the cuspid was swung 
backward and pulled downward until the crown was in a direct 
line with the position it was to occupy when in place. An impres- 
sion was then taken and a vulcanite plate made (Fig. 190), in which 
another spring of piano- wire was inserted in such a manner that 
when properly adjusted the end of the arm reached over and just 
inside of the space of the cuspid. A ligature was then tied around 
the neck of the tooth, and the arm of the spring drawn close to the 
crown and fastened. By glancing at Fig. 190 it will be observed 
that the action of the spring must be to draw the tooth not only 
down, but also inward to its position. In locating the spring in 
the plate, the position of the crown before and after it is brought 
into place must not be lost sight of. When the spring is ap- 
plied for the purpose of drawing the tooth out of the alveolar pro- 



TREATMENT OK SPECIAL FORMS. 



237 



cess, the patient must be seen every day, because in most cases this 
movement is so easily accomplished that only twenty-four hours are 
necessary to complete the operation. If, on the other hand, two or 
more days supervene before the patient is seen, the tooth would be 
erupted further than is required. I have observed such cases. 
Teeth wholly imbedded in the jaw may be erupted with a spring, 
as shown in Fig. 190, by first removing a piece of mucous membrane 
and alveolar process over the crown with Rollins' revolving knife. 
The advantages of this peculiar kind of spring in these difficult 
cases are— 1st, it can be adjusted to any special angle required, and 
2d, the force is constant and need not be readjusted for three or four 
days after it is applied (if the movement is not rapid), thus reliev- 
ing the operator and patient from the expenditure of time in fre- 
quent office attendance. 



Fig. 190. 




A form of irregularity of the teeth is occasionally observed 
wherein the cuspids erupt inside the arch. Sometimes the case pre- 
sents when the point of the cusp has just penetrated the mucous 
membrane of the mouth, and again the tooth will have erupted its 
normal length. Frequently it will erupt in close contact with the 
lateral incisor and first bicuspid, or it may make its appearance in 
the roof of the mouth. Occasionally only one cuspid will be mis- 
placed. Again, both cuspids will thus erupt out of position. The 
object of this article is to demonstrate a simple and easy method of 
correcting these very complicated cases. Fig. 191 illustrates an 
instance of the kind occurring in the mouth of a young lady sixteen 
years of age. Both cuspids were observed in process of eruption 



238 IRREGULARITIES OF THE TEETH. 

inside the arches, and in contact with the adjoining tooth. The 
roots could be outlined on the outer alveolar plate as far as their 
apices, demonstrating the fact that the crypts containing the crowns 
were originally in normal positions, but that their crowns had sub- 
sequently pointed toward the roof of the mouth. A vulcanite plate 
was made, and a hole drilled through it so that the point of a wire 
spring would touch the cuspid just above the margin of the gum. 
On the opposite side of the plate a hole was drilled just deep enough 
to hold the other end of the spring when in position. A small hole 
was then drilled into the enamel (but not through it) just above the 
margin of the gum, to prevent the spring from slipping when ad- 
justed in position. A strong spring was made of piano wire, No. 
3 7 or 18 U. S. gauge, and the ends bent at right angles. One of the 

Fig. 191. 




ends was cut short to fit into the hole made in the plate opposite the 
tooth to be moved, the other end left long enough to pass through 
the plate and sharp-pointed to enter a hole in the tooth to be moved. 
This very small hole was drilled in the enamel of the tooth, for the 
sharp point of the spring to rest in. In many cases such a spring 
wull keep the plate in position, but should the plate slip it may be 
fastened to the bicuspid with ligatures. 

Fig. 192 shows the same irregularity with a different appliance for 
bringing the tooth into place. This appliance is not my own idea, 
but I have been so successful with it for the past seven years that I 
deem it of value to the profession. It is made of German silver, 
which possesses all the requisite qualities. I have three thicknesses 



TREATMENT OF SPECIAI. FORMS. 239 

of it ready for use, N"os. 29, 31 and 32, U. S. gauge. Strips are cut 
T6 to i of an inch in width, according to the strength required, 
and bent with small round-nosed pliers into the shape represented 
at A, to fit the teeth (Fig. 192). This is removed every day, and 
with round-nosed pliers the ends are bent, the spring shortened, and 
forced to place upon the tooth. This little spring acts in two direc- 
tions: 1st, to carry the teeth laterally and thus provide room, and 
2d, to draw the irregular tooth into position. This appliance can 
only be used when the crown of the irregular tooth is fully erupted. 
Teeth situated outside the arch may be thus brought into line as 
well as those which are situated inside. In the latter case it is 
necessary to wear a plate to keep the jaws apart while the tooth is 
in transit. 

A Fig. 192. 




Occasionally, by reason of their tardy eruption, the second bicus- 
pids, and also, but much less frequently, the second molars, become 
locked in between the adjoining teeth, and are thereby suppressed. 
When this has occurred, the grinding surfaces usually are visible 
on a level with the gums, and, of course, operative occlusion with 
the teeth which should properly antagonize the suppressed teeth is 
impossible. 

Fig. 193 is an illustration of the left side of the lower denture of 
a boy thirteen years old, and shows so much of the denture as is 
requisite for the purposes of this brief article. The second decidu- 
ous molar had been retained in the jaw beyond the natural period, 
and its mesial and distal surfiices had been so destroyed by caries 



240 



IRREGULARITIES OF THE TEETH. 



that the first permanent molar had come forward and greatly 
diminished its normal distance from the first bicuspid. The remo- 
val of the deciduous molar left an insufficient space for the ac- 
commodation of the coming second bicuspid, which consequently 
became locked between the molar and first bicuspid, so that com- 
plete eruption was impossible. 

A narrow vulcanite plate was made, and a coiled wire spring 
made and applied as shown in Fig. 193 to force the teeth apart. 
When sufficient room had been gained, a cavity was formed in the 
crown of the second bicuspid, and a small wire eye-bolt set in the 



Fig. 193. 



Fig. 194. 




cavity with amalgam. Another coiled wire spring was fixed in the 
plate, and the spring lever inserted in the eye of the bolt, as shown 
in Fig. 194. The lifting action of the spring soon compelled the 
eruption of the bicuspid into its proper position and relations with 
the occluding teeth. 

The removal of the eye-bolt, after cutting away the amalgam 
with a small round bur, and the subsequent filling of the small 
cavity with gold, completed the operation. 

Obviously a ligature could have been forced down upon the sub- 
merged crown of the bicuspid, and the loop-hitch of the ligature be 
made a substitute for the eye-bolt; but this was preferred as a 
more positive means of attachment to the lifting spring lever. 



CHAPTER YI. 

PKOTRUDING TEETH. 
kingsley's case. 

The following case, with the accompanying illustrations, is re- 
ported by Dr. Kingsley : 

Fig. 195 shows the condition of the teeth of a child of nine years 
of age, for which no adequate cause could be given, as it was not 
hereditary nor the result of thumb-sucking. Treatment was not 

Fig. 195. 




begun until the patient was thirteen years of age, when the perma- 
nent teeth had all made their appearance; and so much did the 
front teeth protrude, that it was with difficulty that the lips could 
be brought together, the incisors being spread or straggled, and the 
crowns of extraordinary length. 

" A frame of gold was made, covering the cutting-edges of the 
incisors and lapping on the cuspids, and a plate of vulcanite 
adapted to the roof of the mouth, and cut away in front to provide 
for the retrocession of the teeth, 

" Ligatures cut from rubber tubing were attached to the poste- 
rior part of the vulcanite plate, one on each side, and drawn for- 
ward and caught on projecting spurs of the gold frame. 

" In a short time the arch in front was contracted until the teeth 
16 241 



242 



IRREGULARITIES OF THE TEETH. 



were in contact, but it was not sufficiently reduced. More room 
being essential, the first bicuspid on each side was removed. The 
incisors had appeared to lengthen during the process (although, 
probably, they had not actually done so), and it seemed that they 
would eventually come down so as to touch the gum of the lower 
jaw. The attempt was therefore made to shorten the crowns by 
driving them up into the jaw. The former appliance was contir- 
ued, and to the gold frame was added a stud or post about one-half 
an inch long, soldered to it opposite the cuspids, and coming out at 
each corner of the mouth." This apparatus is shown in Fig. 196. 



Fig. IQfi. 




The arms, extending upward, passing outside the cheeks, were 
made of strips of brass and connected by elastic ligatures, with a 
leather skull cap, as shown in Fig. 197. 

The vulcanite plate was inserted in the mouth, and the rubber 
ligatures brought forward and caught; the skull cap was then 
placed on the head, and strong elastic straps were caught over but- 
tons or hooks on the cap, and like buttons or hooks on the cheek- 
arms, as shown in Fig. 197- The outside pressure thus forced the 
teeth up into the jaw, and the inside pressure drew them backward 
in a direct line. The apparatus did not interfere with the comfort 
of the patient, and was worn for three months constantly, and part 
of the time for two months more, at which time the six front teeth 
were carried backward so that the cuspids came in contact with 



PROTRUDING TEETH. 



243 



the second bicuspids, and the incisors were driven up into their 
sockets one-quarter the length of their crowns, with the result 
shown in Fig. 198. 



Fig. 197. 




FAKEAR'S CASES. 



When the abnormal protrusion of the six upper front teeth is very- 
marked, the correction of the irregularity may require a greater 
degree of anchorage than is offered by the posterior teeth. Dr. 



Fig. 198. 



|niiiii|ii|)i|||[lj|!|:iniiii!iiiiii^^ 




Farrar has devised an apparatus to meet such cases, known as a 
" bridle apparatus," which is illustrated in Fig. 199. 

This is constructed as follows : " A gold strap of rolled wire, 



244 



IRREGULARITIES OF THE TEEEH. 



having a smootli nut on each end, is bent to conform to the anterior 
surface of the four or six front teeth, and so fastened bv means of 
screws to clamp bands on the posterior teeth, as shown in Fig. 201. 

" To prevent this band from slipping up toward the gum, troughs 
have been tried, but they collect food and injure the teeth. I use one 
or more T pieces made to fit between the teeth, soldered to the 
band, or to ferrules sliding on the band (Figs. 201 and 204;, or to 
broad plate hooks '^Fig. 205). 

" Another plan of attaining this end is bv the use of a round wire 
resting upon the lingual surfaces of the teeth, connected in the 




same way to the front band. The nearer these front wires ap- 
proach the cutting-edges of the teeth, the le^ power it requires to 
move the teeth. 

" The front band is connected with the outside apparatus by 
means of cylindrical or angular ferrules, or staples soldered to it 
at points opposite the spaces between the laterals and cuspids. 
Through these ferrules or staples, which are at a sufficient distance 
from the comers of the mouth to prevent the dribbling of saliva, 
are hooked bent cheek-wires, gold (about Xo. 12 gauge), that pro- 
ject forward and outward, thence pointing toward the ears on a 
line with the front band (Fig. 199). To prevent the falling over of 
this curved cheek-wire, one side of the ferrule portion may be filed 



PROTRUDING TEETH. 



245 



flat, and the ferrule shaped to correspond by a blow from a 
hammer ; but this is seldom necessary. 

" In some cases, in which detachment of the two parts is of no 
consideration, the cheek-wires may be soldered directly to the front 
band-piece (the retaining portion of the inside apparatus being 
dispensed with. Fig. 202, or double band, as shown in Fig. 203.) 
The outer extremities of these cheek-wires are screw-cut for drag 
nuts, one modification of which is illustrated by By 203. 



Fig. 201. 




" These wires may be in two or more pieces, but as this causes 
a pressure upon the cheek, which may crowd upon the anchor 
apparatus inside of the mouth, it is much better to make the 
cheek-wire in one piece, which, if bent properly, will arch from the 
cheek to the ear-ring, without being in contact with the cheek. 

"In fact, my experience teaches me that the latter is much 
the better form. The screw extends through the holes in oppo- 
site sides of a small ring, which is caught on one of several hooks 
soldered to a much larger ring extending around the ear of the 



246 



IRREGULARITIES OF THE TEETH. 



patient (Fig. 199). This larger ring (which is necessary to pre- 
vent interference with the ear) is fastened to inelastic straps ex- 
tending around the back of the head and held in place by other 
straps, as shown. The lower straps and ear-rings constitute the 
anchorage apparatus. The ear-rings should be about two and a 



Fig. 202. 




half by three inches in diameter, underlaid by soft leather or 
felt rings about one-quarter to one-half inch wide, to serve as 
cushions to protect the skin. In order to have these rings rest 



Fig. 203. 




in their proper places around the ears, and to permit the har- 
ness to bear equally, so as to prevent headache, the several straps 
should be made capable of being tightened or loosened at will by 
means of buckles. 



PROTRUDING TEETH. 



247 



" When the apparatus is in position, the friends of the patients 
are instructed to tighten the posterior bands or to turn the nuts 
within the smaller rings daily. The patient is advised to call at 
the office once or twice a week, when, if the position of the teeth 
has changed sufficiently to render the front bands liable to slip off, 
the direction of the traction should be changed by raising the nut 
ring from a lower hook on the ear-ring to one higher." 




Fig. 205. 




Fig. 206 illustrates a device for the same purpose, exhibited to 
the profession by Dr. Farrar in Nov., 1885. This appliance con- 
sists of bands of gold or platinum, extending around the molars and 
bicuspids upon either side of the arch. A nut is soldered upon the 
buccal surfaces for carrying a long screw. A band of gold encir- 
cles the arch, and is secured by hooks midway between the cutting- 



FiG. 206. 




edges and necks of the incisor teeth. The ends of the band are 
bent at right angles, having holes through the ends for the free 
movement of the screws. The bands and teeth enclosed are the 
fixed points, and by turning the screws twice a day the anterior 
teeth are carried to the posterior part of the alveolus. This appli- 
ance claims cleanliness and the advantaoje of beiui? out of slight as 
its strong points for its recommendation to our use. 



248 IRREGULARITIES OF THE TEETH. 



TKEATMENT OF ANTERIOR PROTRUSIONS OF THE SUPERIOR 
DENTAL ARCH. 

The Author's Method. 

The etiology of this class of cases is gi vea on page 159. A typical 
case is here described with sufficient minuteness to be of use to those 
who have never attempted the correction of such, presenting points' 
of interest even to one who has had considerable experience in reg- 
ulating. 

M. C, a boy fifteen years of age, presented the following condi- 
tions : The lower incisors struck against the palate, back of the 
basilar ridge, and the first bicuspids of the upper jaw stood entirely 
outside of the lower ones. The articulation of the second bicuspids 
and lower molars was imperfect. In consequence of the irritation 
that preceded the protrusion the upper alveolar process was mon- 
strously developed. This display of gums and teeth, exaggerated 
by a very short upper lip, disfigured the boy, who otherwise had an 
interesting and agreeable face. 

A rubber plate was placed in the mouth, fitting the vault, and of 
sufficient thickness in front to separate the posterior teeth, in order 
to lengthen them, and to force the lower incisors into the jaw. This 
was renewed once or twice to give additional space. When this pro- 
cess was completed so as to leave a space of three-sixteenths of an 
inch between the vault and the lower incisors, a spring plate 
was inserted in the lower jaw, extending as far back as the 
shortest diameter of the lower arch. When first introduced it was 
left without the spring to accustom the wearer to the annoyance. 
Then holes were bored opposite the lower first bicuspid, and short 
pegs inserted, which by absorption of moisture spread these teeth. 
These were removed and lengthened slightly. Then the spring was 
put iu. In this case a plate in the vault to which the first upper 
bicuspids were attached by means of ligatures aided in bringing 
them in. Sufficient time was allowed for these steps, so as not to 
exhaust the patient too much. When the strain proved too great 
he was taken out of school and allowed to be in the open air as 
much as possible. About three months elapsed before these steps 
were completed and an attempt was made to bring in the incisors. 
The centrals were first acted upon alone, as the excessive prolifera- 
tion of bone-cells in the process and the maxillary bone in each case 



PROTRUDING TEETH. 249 

affords great resistance, and it is difficult to make an apparatus to 
meet this difficulty. To attach the front teeth to the back teeth by 
means of ehistic or metal bands often results in embarrassment, as these 
will loosen while the front teeth remain firm. A number of in- 
genious apparatuses have been devised by professional gentlemen of 
reputation, combining sliding metal bands and elastic bands attached 
to posterior teeth. These work in some cases, but in those in which 
great resistance is offered they have proved a failure in the experi- 
ence of the author, moving the molars or bicuspids forward instead 
of the front teeth backward. Such cases have occurred in the 
author's practice a number of times. It is best, therefore, to loosen 
one or two at a time. Sometimes the first steps can be taken most 
advantageously by simply inserting rubber ring wedges between the 
incisors, making them more easily acted upon. In this case liga- 
tures were attached to the two central incisors, and thf se attached 
to a plate covering the vault, but not near the anterior margin but 
to the centre, for the purpose of distributing force. The ligatures 
were then changed to a band extending over the central incisors, to 
which hooks were attached. 

This apparatus is of limited efficiency, as the force of the band is 
spent in part in the anterior margin of the plate over which it 
passes. The central incisors having been moved, to some extent, 
it was thought desirable to bring in the laterals as well, by means 
of an appliance exerting greater force. A cap of linen and tape 
was made, buckling tightly at the back of the head. Three strips 
of tape converged back of the ear. To these and the linen band 
passing around the head, rings of piano-wire covered with zephyr 
were sewed. In front of these rings loops of wire had been pre- 
viously soldered for the attachment of elastic bands and ligatures. 
It is not desirable to make the cap of elastic bands because the 
rubber, when worn for some time, irritates the scalp, and there is a 
tendency to slip up and down. In making the appliance the slope 
of the head must be taken into consideration, for which reason care 
must be exercised in filling. The appliance was inserted into the 
mouth, to which the rubber bands were attached by ordinary liga- 
tures. The length of the arms (Dr. Goddard's appliance) decidedly 
increased the elasticity and efficiency of the apparatus 

The patient came to the office twice a day to have the case in- 
spected and such changes made in the adaptation of the appliance 



250 IRREGULARITIES OF THE TEETH. 

as seemed necessary. Such changes are by no means infrequent, as 
the pressure will be unequal, no matter what care is exercised, for 
which reason there will be more or less soreness in spots. The 
tightening of the ligatures produces a similar result. Careful watch- 
ing in such cases is necessary, and there must be an occasional day 
of rest, during which a retaining appliance should be worn. 

After three months, making six months in all, the patient's 
upper jaw was nearly normal, and he was dismissed. 

PEOTEUSIOX OF THE INFERIOR MAXILLA. 

Allan's Case. 

Fig. 207 represents a case of protrusion of the inferior maxillary 
treated by Dr. George S. Allan, of Xew York. 

The irregularity pertaining solely to the jaw, that alone was oper- 
ated upon. A brass plate was made to fit the chin, having arms 
with hooked ends arranged so that the distance between them could 
be altered by pressing them apart or together. A network was ad- 
justed upon the head, having two hooks on each side, one above 
and the other below the ear, to which were attached four ligatures 
of ordinary elastic rubber. The operation proceeded rapidly, and 
at the end of two months the irregularity was almost entirely cured. 
In this operation the result was attained by pushing back the con- 
dyles of the jaw into the glenoid cavity, the interarticular cartilage 
giving way and absorption taking place posterior to the condyles, 
with a filling in at the anterior side. 

METHODS OF RETENTION OF THE TEETH AFTER REGULA- 
TING. 

NTo element of regulating the teeth is more difficult than that of 
securing the teeth firmly after they have been forced into their new 
positions. The inclination to return to their original places is in- 
creased when the teeth are moved faster than the physiological 
process of filling in new material is accomplished. Pressure of the 
lips and tongue exerts influence in producing backward and lateral 
pressure upon the teeth. The greatest help in this direction is to 
so plan the operation, either by extraction or by inward or outward 
pressure (as the case requires), that when completed the posterior 
teeth will occlude in such a manner that they will hold one another 
in proper positions. Dr. Kingsley, in his " Oral Deformities/' says : 



PROTRUDING TEETH. 



251 



"The articulation of masticating organs is of much more import- 
ance than their number, and a limited number of grinding teeth 
fitting closely on occlusion will be of far greater benefit to the 
individual than a mouthful of teeth with the articulation dis- 
turbed."* 

Fig. 207. 






l\ 



\ 







Occlusion, however, will not retain the anterior teeth in position. 
Nor will it be safe to depend entirely upon occlusion to hold the 
posterior teeth in position. In most cases other means must be de- 
vised for holding the anterior teeth in position. Cases of this kind 
are apt to be those in which the arch of the superior or the inferior 
maxilla has been spread or the anterior teeth have been moved 
inward or outward. It is then frequently necessary to spread both 
arches by simply carrying the teeth of one jaw out to the proper 
distance and securing them with a retention plate ; the teeth of the 
opposite jaw will, in most cases, be forced into their positions by 
their grinding surfaces coming in contact in mastication. Fig. 208 
shows one of these retention plates: It fits the roof of the mouth 
and teeth accurately, and can be readily removed for cleansing. 



* Op. cit., p. 43. 



252 



IRREGULARITIES OF THE TEETH. 



Such a plate is of service upon either jaw for preventing one or all 



the teeth from rotating 



back toward the inner part of the mouth. 

Fig. 208. 




KINGSLEY'S EETAINEE. 

For holding the anterior teeth in position, the appliance recom- 
mended by Dr. Kingsley answers the purpose admirably. It con- 
sists of a rubber plate fitting the teeth and the roof of the mouth, 
and having a band of platinum or gold secured to it. The band 
passes through a separation in the teeth upon either side, and im- 
pinges upon the labial surfaces of the anterior teeth, as represented 
in Fig. 209. This application will not serve when the teeth are 
crowded. 

KICHAKDSON'S RETAINERS. 

Where all the teeth in the jaw have been moved, particularly if 
some have been rotated into position, a retentive plate that comes 

Fig. 209. 




in contact with all the teeth should be used. A rubber plate will 
fit each tooth accurately without trouble or expense. Dr. Richard- 



PROTRUDING TEETH. 253 

son gave his retentive plate to the profession many years ago, and 
in many respects it cannot be improved upon. Fig. 210 illustrates 
this appliance. It is composed of two pieces of rubber, vulcanized 
upon the labial and lingual surfaces of the teeth of the plaster 
model. These are trimmed to about a quarter of an inch in width, 
and fitted to the necks of the teeth and gums. When a tooth is 
missing upon either side of the jaw, or when spaces exist between 
the teeth, or there is room behind the molars, the rubber may ex- 
tend from the outer to the inner plate, and thus the two pieces be 
made into one. If, as in the illustration, there be little or no room 
to carry the rubber from one piece to the other, flattened or round 
gold wire may be vulcanized or riveted so as to hold the wire in 
position. The only objection to this appliance is its unsightly 
appearance. It can, however, be removed by the patient for clean- 
sing. 

KUBBEE PLATES WITH GOLD BANDS AND BAES. 

When single teeth have been rotated in their sockets, or moved 
in or out for the purpose of perfecting the contour, a simple 
arrangement for retaining the teeth is to fit a rubber plate to the 
palatine or lingual surfaces of the teeth, and attach a bar or clasp 
of gold to the teeth that have been moved. Fig. 211 illustrates a 




retaining plate Avith a bar attached for holding the superior central 
incisors in their position after regulating. The bicuspids and molars 
may be treated similarly. 

Rubber retainers are apt to be inconvenient for cleansing prop- 
erly. Patients are inclined to be careless on this account, but 
should be instructed to attend to this duty after each meal, to pre- 



254 



IRREGULARITIES OF THE TEETH. 



vent the secretions from becoming vitiated, the gums inflamed and 
the teeth decayed. Great improvements in these appliances have 
been made in the past few years, as will be observed on examining 
some of the methods below. 



Fig. 211. 




FARRAK'S RETAINERS. 

Dr. Farrar, of New York, has invented some ingenious appli- 
ances for holding teeth in proper positions ; among these are his 
clamp bands. Some are composed of one piece of gold, others of 
two pieces. Fig. 212 represents one form made from square^ 
18-carat gold wire. This will take a size to correspond with the 
tooth and the amount of resistance required to hold it in place. 
A thread is cut from one end to about a third of its length ; the 
remainder of the wire is rolled or hammered into a thin band, 
about Ko. 35 or 36 American gauge, and about one twenty-fourth 
of an inch in breadth. At the distal end a hole is drilled, large 
enough to allow the screw end to pass through with a thread cut upon 
it. Small projections should be soldered upon the band and bent 
so as to catch upon the tooth. When two pieces of gold are used, 



Fig. 212. 



Fig. 213. 



Fig. 2 '4. 






the band is made in the manner described in the first case, and bars 
of the same carat gold rolled to Nos. 22 and 23, American gauge. 
One end of the bar is bent to an angle of forty-five degrees to pre- 



PROTRUDING TKETH. 



255 



vent the band from slipping. Near the other end of the bar a 
hole is drilled for the passage of the screw end of Fig. 213. 

By adding rings to either kind of bands they may be used for 
anchor bands. Fig. 214 shows how they are used as a retaining 
band while in position. 

DE. GUILFOKD'S EETAINEE 

Dr. Guilford's retainer consists of a band of gold or platinum 
(Fig. 215) swaged or fitted accurately to the tooth and of sufficient 
strength to resist the rotary strain and friction in mastication. By 



Fig. 215. 



Fig. 216. 



trimming the labial surfaces as narrow as compatible with strength, 
the band will not appear conspicuous. It should be adjusted mid- 
way between the cutting and grinding edges of the gum, and there 
cemented to the tooth with oxyphosphate of zinc. This can be 



Fig 217. 




worn indefinitely without affecting the gums or teeth, and can be 
cleansed perfectly ; hence the bands, bars or levers may be firmly 
soldered for rotating or retaining the teeth after regulating. Fig. 
216 shows the application of two of these bands when two teeth are 
secured in position by a bar extending past fixed teeth on both 
sides. When two or more teeth are to be held in position, the 
bands may be secured to the bicuspids or molars on both sides, and 
a bar of gold extended from one to the other, upon the lingual or 
labial surface, as illustrated in Fig. 217, from Dr. Guilford's collec- 
tion. " Platinum bands were fitted to the two cuspids, and these 




256 IRREGULARITIES OF THE TEETH. 

were connected by a very thin platinum wire passing along and 
conforming to the outline of the labial surfaces of the incisors." 

The Author's Ketainer. 

This retainer consists of a band of platinum or gold fitted to the 
tooth or teeth, with a tube of the same material, the width of the 
tooth, soldered lengthwise of the band, as illustrated in Fig. 218. 
The band is fastened to the tooth with oxyphosphate of zinc, and a 
Fig. 218. piccc of gold, platinum or piano- 

wire is passed through the tube 
and allowed to come in contact 
with the surface of a firm tooth. 
Should the tooth that has been 
regulated move, the wire may be 
bent so that the tooth may be re- 
stored to its proper position. Two or more teeth may be retained 
in the same manner. The tube may be attached to the labial, 
buccal, palatine or lingual side of the band, according to the re- 
quirements of the case. 

Length of Time Eequired to Eetain the Teeth in their Place. 

Two reasons governing the time required to retain the plate 
upon the teeth are, first, the age of the patient ; second, the nature 
of the operation. The time cannot be definitely stated for all per- 
sons, even of the same age and condition of case ; an approximate 
period only can be fixed. In young and healthy persons, in whom 
reconstruction of tissue is rapid, the retainer will be needed but a 
comparatively short time. If the superior or inferior arches have 
been enlarged, a retaining plate must be worn until all the teeth 
have accommodated themselves to their new position — a period that 
will vary from six months to a year. 

Where the teeth have been forced into the arch little or no re- 
tention will be required, the pressure of the lips and cheeks often 
being all that is necessary. Occlusion of the teeth of the opposite 
jaw aids greatly in retaining the bicuspids and molars. 

The most difficult teeth to retain are those that have been ro- 
tated in their sockets. The difficulty of correcting the tendency to 
return to their original positions is so great that the retainers must 
be kept in place from one to two years, and occasionally even 



PROTRUDING TKKTH. 257 

longer than this. The operator will have to use his best judgment 
as to the proper time to remove them. The number of teeth being 
moved does not affect the time required, as the bone is as rapidly 
deposited in one part of the jaw as another. The health of the 
patient will have considerable influence in the time required. A 
strong, robust person will recover from the operation more rapidly 
than one that is anaemic. The retainer should remain as long as 
circumstances will warrant, when a model should be secured. After 
the lapse of not longer than a day, an examination should be made. 
If the teeth have not deviated, a week may elapse before making 
another examination. These examinations should be continued 
until the operator is satisfied that the teeth are secure. If the teeth 
should move, the retainer must be replaced, and allowed to remain 
for from three to six months, when it can be removed, and if any 
deviation is noted, it should be returned and worn until the teeth 
will remain as desired. 



ii^riDEix:. 



PAGE 

A GE for correcting deformities 171 

Allan's case of protrusion of inferior 

maxilla 250 

Alveolar process' 30 

flexion of, causing irre- 

gularities 129 

inferior 32 

hypertrophy of ... . 39 

■ forward movement of . 168 

Anomalies from functional derangements 73 

in idiots, insane, etc 73 

transmitted 42 

Arch, dental, normal 104 

combined saddle and V- 

shaped 124 

saddle shaped 118 

modifications of 122 

of lower teeth . 126 

spreading 220 

superior, anterior protru- 

sions of 248 

Talbot's method for 248 

V-shaped . 102 

how formed . . 103-105 

modifications of . . 108 

semi- 112 

Asymmetry of lower jaw, causes of . . . 59 

of maxillary bones 56-61 

rami 63 

in body of maxilla 64 

Axle 197 

glCUSPIDS, lower 154 

deflection of 141 

late eruption of 141 

malposition of 141 

Blind, jaw deformities among 80 

Bones, maxillary, arrest of development of 42 

arrested growth and de- 

velopment of ... . 50 

asymmetry of 56-61 

Byrne's method 210 

pHILDREN, deformities of jaws in . . 81-82 
Civilization, effect of, on dental defor- 
mities 24 



PAGE 

Climate, effect of, on arrested maxillary de- 
velopment 42 

Coles on abnormal heads 93 

Consanguinity and deformities 81-84 

Crowns, moving 232 

Farrar's method 234 

Cuspid, inferior ... . 153 

Cuspids, malposition of 137 

"pvEAF and dumb, defonnities in . . . 78. 79 
Deformities, among non-defective , 81 

dental, diathesis 52 

of the jaws 75 

maxillary, in deaf and dumb 

74, 78, 79 

of the blind 80 

of idiots 74 

among insane 80 

and consanguinity 81 

Deformity, Haskell's 61 

Dental arch, spreading 220 

superior, anterior protrusion 

of 248 

Talbot's method for 248 

Development, arrest of, and excessive max- 
illary growth 50 

of maxillae, exercise in . . , 54 

arrested, from race-crossing, 

climate and soil 42 

Diagnosis of irregularities 170 

Diathesis and dental deformities 52 

Drunkenness, parental, and idiocy .... 86 

"PDUCATION, intra-uterine 87 

Elastic force 202 

Eruption, vicious, of incisors 13J 

Exercise, in developing maxillff' 54 

Extraction of first molars 143 

premature, of temporary teeth 22 

"PARRAR'S bridle apparatus 243 

method 208 

of moving crowns 234 

of rotating 227 

retainers 2.'>4 

Fe»!8 for operations 186 

251) 



260 



INDEX. 



PAGE 

Force, application of 192 

Forces, mechanical 192 

pUILFOED'S method of rotating ... 230 
retainer 255 

TTASKELL'S deformity 61 

Headridge-CoflSn method 215 

Heads, abnormally shaped 91 

Health, and correction of deformities . . 173 

Howe, on consanguinity 84 

Hypertrophy of alveolar process 39 

TDIOCY, and scrofula 85 

and parental drunkenness . . 86 

Idiots, anomalies in ; . . . . 73 

brain of 89 

development of 89 

maxillarj' deformities in .... 74, 75 

protruding superior maxilla in . . 65 

stature aud weight 90 

Incisors, central, malposition of, from vi- 
cious eruption .... 132 

lateral, malposition of 134 

part of, in causing irregularities . 129 

Irregularities, caused by thumb-sucking . 166 

diagnosis of 170 

age for correcting .... 171 

correction of 207 

Byrnes' Method 210 

by rotation 227 

Farrar's method 208 

Headridge-CofBn method . 215 

Patrick's method ...... 207 

Talbot's method 218 

special forms of 227 

use of piano wire 218 

health and 173 

constitutional 77 

causes of . 25, 42 

effect of civilization on . . 24 

historical sketch of ... . 17 

from constitutional causes . 102 

consanguinity and sedentary 

life 83-84 

from malposition of bicus- 

pids 141 

of cuspids 137 

of incisors 129 

of lateral 

incisors 134 

extraction of first 

molar 134 

vicious eruption . . 132 

local causes of . . . 128 

of lower law 148 



Irregularities, from malnutrition .... 73 

overstimulation . 73 

importance of individual 

teeth in causing .... 128 

part of incisors in ... . 129 



TAW, lower, asymmetry of 59 

local irregularities .... 148 

Jaws and teeth, want of proportion be- 
tween 28 

anomalies of 73 

hereditary defects and malformations 

of 95 

deformities of, in the blind .... 80 

deaf and dumb 79 

T7"INGSLET, causes of an interior pro- 
trusion 160 

Kingsley's case of protruding teeth . . . 241 
retainer 252 

T EVER 195 

1VTALP0SITION of bicuspids .... 141 

cuspids 137 

lateral incisors . . 134 

Matteson's method of compulsory eruption 235 

Maxilla, deformed, in the non-defective . 81 

development of, exercise in . . 54 

lower, irregularities of . .... 148 

inferior, protrusion of . . . .68, 250 

Allan's case . 250 

superior, protruding in idiots . . 65 

Maxillae, arrest of development of ... . 42 

arrested development 50 

asymmetry of 56, 01, 64 

efi'ect of neurotic tendencies on 95 

growth of 21 

irregularities, historical sketch 17 

Maxillary body, asymmetry of 64 

deformities, in deaf and dumb 

74, 77, 78 

idiots 74 

Migration of teeth 155 

Models, study of, etc 176 

Molar, first, extraction of 143 

Morel, on neurotic tendencies 95 

Moriarty, table of irregularities .... 83 

Mouth, impressions of 176 

open, in sleep 21 

"M'EUROTIC tendencies, causing defects 

of the jaws 95 



INDEX. 



261 



PAGE 

QCCLUSION, imperfect 66 

improper 64 

Ossification, premature 92 

Ottofy, on deformities among the appar- 
ently non-defective 81 

Overbreeding, effect of 98 

PATRICK'S method 207 

Piano wire 218 

Plane, inclined 198 

Pre-natal influence 87 

Pressure 190 

Process, alveolar 30 

inferior 32 

hypertrophy of . . 39 

forward movement of . . . 158 

flexion of, and irregularities 129 

Prognathism 72 

Protrusion of inferior maxilla 250 

Allan's case .... 250 

Protrusions, anterior 155 

causes of 159 

of anterior superior dental 

arch . 248 

Talbot's method 

for 248 

Pulley 197 

"DACE-CROSSING, effect of, in causing 

irregularities 42 

Rami, asymmetry of 63 

Retention of teeth after regulation, . . . 250 

by Farrar's retainers, 264 

by Guilford's retainer, 255 

by Kingsley's retainer, 252 

by Richardson's do. 252 

by rubber plates, . . 253 

by Talbot's retainer, . 256 

time required for, . . 266 

Richardson's retainers, 252 

Rubber plates, retention by 253 

Roots, moving, 232 

qCREW, 200 

Scrofula and idiocy, 85 

Scrofula and irregularities, 85 

Shuttleworth, brain of idiots 89 

Soil, effect of on irregularities, 42 

Sphenoid, development of, 24 

rpALBOT'S method, 218 

of compulsory erup- 

tion, 236 



PAGE 

Talbot's method of rotating, 231 

of treating anterior pro- 

trusions of upper dental 

arch, 248 

retainer, 256 

Teeth, anterior protrusion of, 155 

causes of, . . 159 

changes of, 189 

deformities of, and diathesis, ... 52 

' eruption of, compulsory, 235 

Matteson's method, . 235 

Talbot's, 236 

forward movement of, 158 

incisor, in irregularities, 129 

vicious eruption of, ... 132 

individual, regulating, 223 

movement of, ... . 157 

rotation of, 158 

irregularities of, effect of civiliza- 

tion on, 24 

irregularities, constitutional, ... 77 

causes, 25, 42 

historical sketch of, 17 

jaws and want of proportion be- 

tween, 28 

malformations of, hereditary de- 

fects and, 95 

migration of, 155 

protruding, 241 

Farrar's apparatus foi-, 243 

Kingsley's case, . . . 241 

rotating, Farrar's method, .... 227 

Guilford's method, ... 230 

Talbot's methods, . . 231 

retention of, after regulation, . . 250 

by Farrar's retainers, . 254 

by Guilford's retainer, . 255 

by Kingsley's retainer, . 252 

by Richardson's retain- 

ers, 252 

by Talbot's retainer, . 256 

time required for, . . . 256 

supernumerary 17, 162 

temporary, retention of 20 

premature extraction of, 22 

Thumb-sucking, IS 

and irregularities, . . 166 

TTOISIN, on abnormal heads, 01 

WEDGE 109 

•^ Wheel, 197 

Wilniarth, brain of idiots SO 






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